No problem getting front wheel off, problem putting it back on,does not center so you can mount calipers. help

Remove brake caliper mounting screws from where they mount on the front forks. Slide caliper off brake disc and secure caliper
out of the way. Do not operate the front brake lever with the front wheel
removed or the caliper pistons may be forced out. Reseating the pistons requires disassembly of the caliper. On models with dual disc brakes, remove both calipers.

Remove axle nut lockwasher and flat washer from axle on left side of vehicle.

On right side of vehicle, loosen nut on pinch screw. Pull axle out of hub while supporting wheel.

Remove spacer and front wheel assembly.

Keep track of where each of the different size spacer went so you can put the back in the same order when reassembling.

For reinstall, you should get a manual as you will need to get torc specs. and other spacing and assemble instructions.

If you mean your front brake discs behind the wheel, then jack up the car, pull off the wheels first.Once your wheels are off you need to take off the brake caliper.That is the piece where the brake pads are located.usually 2 bolts (metric) holds them on.Once the calipers are out of the way,you either have brake rotors that are held on by set screws in the face of the rotor, or you have to take off the center nut in the hub and the caliper mounting bracket for the rotors to come off.Tear down one side so you can use the other as a guide to help you put it back together.

Front brakes are very simple to do:

• Pull off the front tires.
• Remove the brake pads by removing the slide pin bolts where the piston assembly attaches to the caliper mounting bracket. The slide pin bolts are usually a 12 or 14mm bolt. Once the piston assembly is free slide the old brake pads out.
• Compress the piston back into the caliper by using a large pair of channel lock pliers or a c-clamp. If you don't do this, you won't be able to get the new pads on.
• Before you put the new pads on, replace the rotor.
• Remove the two bolts for the caliper mounting bracket. They are in the back and are bigger than the slide pin bolts. Usually a 17 or 19mm bolt.
• Pull off the caliper mounting bracket.
• At this point the old rotor should slide right off. If it doesn't slide right off, look for a screw in the center of the rotor, some cars will have a screw there to hold the rotor on. If there's no screw and it still won't come off, try tapping it with a hammer. If you're replacing the rotor, don't be shy.
• Put the new rotor on. Make sure to clean off any grease with brake cleaner that may be on the braking surface from packaging.
• Put the caliper mounting bracket back on.
• Put the new brake pads on. Make sure to use some anti-squeal grease on the back of the pads.
• Put the caliper assembly back on with the slide pins. Grease up the slide pins as well.
• Put the wheels back on.
• Make sure to pump your brakes 10 - 15 times before you drive off. Because you compressed the piston back into the caliper, the piston will not be contacting the brake pads unless you pump the brakes.

Good Luck!
~Brandon

Front brake
Step 1: Identify Front Disc Brake Components

Front Wheel Drive Brake Assembly
Most front disc brake components include: brake rotor, brake pads, brake caliper, caliper mount and brake flex hose. Brake service usual occurs between 20,000 and 40,000 miles depending on driver habits, road conditions and brake pad/ rotor materials used.
Step 2: Remove Brake Caliper to Replace Pads

Removing Brake Caliper Mounting Bolts
Locate primary caliper mounting bolts; apply wrench pressure counter-clockwise (When looking at the head of the bolt) to remove the bolts, upper and lower. Make sure the bolt threads are in good shape and replace if necessary.
Step 3: Remove Front Brake Caliper

Remove Front Brake Caliper
After removing the primary caliper mounting bolts lift the brake caliper off of the rotor and then tie or secure to the side, being careful not to bend or kink the brake caliper flex hose. Thoroughly inspect brake caliper and brake hoses for leakage, cracks or chaffing and replace as needed. Next remove the brake pads (If not mounted in the caliper) and secondary caliper mounting bolts. Notice how great protective gloves work, most technicians use them on the job today.
Step 4: Remove Brake Pads

Remove Front Brake Pads
Once the brake pads have been removed, make sure if there is anti rattle hardware to transfer to the new brake pads. Some brake pad manufacturers will include the proper lube (Caliper slides) and anti-rattle hardware to ensure proper performance of their product.
Step 5: Remove Caliper Mount

Remove Caliper Mount Bracket
Finish removing secondary caliper mount bolts and remove caliper mount. Note: clean and lube caliper slides and pad friction surfaces of all foreign material or build-up.
Step 6: Remove Brake Rotor

Remove Brake Rotor
With the caliper mount out of the way you can now remove the brake rotor. Sometimes it can get stuck so you may need to tap it with a hammer or use penetrating oil to free it up. Some manufacturers use small screws to hold the rotor on as well. Clean and inspect wheel studs, replace if any are damaged. Also clean bearing hub rotor mount surface to ensure the proper mounting of the new brake rotor. Inspect the ABS sensor wheel for cracks or damage and replace as needed.
Step 7: Depressing the Brake Caliper

Resetting Brake Caliper
To install the new brake pads you must retract the brake caliper piston. Remove the master cylinder lid or open the brake caliper bleeder screw to allow excess brake fluid to be released if necessary. Install C clamp tool and gently tighten clamp until caliper piston is fully depressed. Note: use old brake pad to protect the caliper piston. Close the bleeders once the piston is retracted completely
Step 8: Installing New Brake Rotor

Install Brake Rotor
Install new brake rotor, the new rotor is manufactured with a protective film over the rotor to keep it from rusting, remove protective film with brake cleaner before installing; also after the brake job is complete you may experience a small amount of smoke from the rotor when first used. This is normal and will go away after the first couple of uses.
Step 9: Installing New Front Brake Pads

Installing New Brake Pads
Reinstall the front brake caliper mount, and then install front brake pads. Make sure the pads are seated properly in the caliper mount; it must be a close fit to work properly..
Step 10: Reinstall Front Brake Caliper

Re-Install front Bake Caliper
Reinstall front brake caliper and reinstall caliper-mounting bolts, recheck all mounts and mounting bolts. Check the caliper slides to be sure there is no bind and that the caliper moves freely back and forth on the caliper slides. Bleed brake system per manufacturer's specifications to relieve any air trapped in the system. Before driving the vehicle, push the brake pedal down and let it up slowly, repeat until normal brake pedal operation resumes, this operation is forcing the brake pads to travel to the brake rotors.

Center stand the bike, place a jack under the motor but do not lift yet,unbolt calipers and hang with wires, loosen the four nuts and washers on the bottom of fork on nut looking end of axle(nut should turn but may not be tight), loosen nut on axle, now take off all nuts washers,and pull off two caps. Now slowly jack up motor to rock bike back on center stand, just enough to roll wheel out the front. When putting caps back on make sure arrows on the caps are pointed forward. Also use feeler gauge in tool kit (or eyeball it) to make sure discs are centered in caliper slots and not rubbing against calipers(before tightening eight nuts on fork bottom caps. Also make sure speedo gear is positioned correctly(not binding) and wheel spins freely before dropping wheel. It takes some fiddling around to put this front wheel back on. Minor adjustments are made by spinning the axle nut to adjust fork spacing.

(front) remove the wheel and brake caliper along with attaching parts. remove the center nutand abs sensor connector if mounted on the back side. remove the bearing hub mounting bolts on the inside (4). remove hub and reverse this proceedure to install. the rear is mounted the same way

take the front wheels off,remove the 2 bolts holding the caliper to the caliper mounting bracket and then remove the caliper and then take the old pads out while you remember which ones went where and the put the new ones on the mounting bracket and then get a pliers to push the caliper piston in so they fit over the new thick pads and then slide the caliper over the new pads and then put the 2 bolts back in and then the wheel, then the other side

Removal & Installation

1. Before servicing the vehicle, refer to the precautions section.
   
2. Remove or disconnect the following:
   
   • Wheels
     
   • Pad retaining clip
     
   • Cap from the bottom caliper bolt
     
   • Lower caliper mounting bolt and swing the caliper up
     
   • Brake pads
     

To install:

1. Press the caliper piston back into the cylinder using tool 49 0221 600C.
   
2. Install or connect the following:
   
   • Outer pad to the mounting support and inner pad to the caliper
     
   • Caliper. Torque the caliper lower mounting bolt to 19–22 ft. lbs. (25–30 Nm). Install the bolt cap.
     
   • Retaining clip
     
   • Wheels
     
3. Pump the brake pedal several times to seat the pads.
   

Press the front caliper piston back into the cylinder—Mazda3

is this front wheel? rear wheel? or 4 wheel drive? if you have front wheel drive or 4 wheel drive you will need to take the tire off and get the center cap off with cotter pin on most vehicles. then put the tire back on without its center cap. then put the vehicle back on the ground. then use required socket with an extention and breaker bar to put through the rim to loosen center hub bolt about a quarter turn. just enough to break it loose. then take the tire back off to finish the job. remove the brake caliper and rotor then center nut on hub bearing. there should be 3 bolts from the inside holding hub bearing on. on rear wheel only you won't need to take the tire off and on.

Jack up the front end - SAFELY...
Put on jack stands so the front wheels are hanging.. Chalk the rear wheels..
Pull the tires off..
Disconect the calipers. Usually takes a allen wrench..
Pop out the old pads..
Before snapping the new ones in you need to open up the calipers..
Open the master cap under the hood..
To open the caliper I use a seaclamp.. Set the seaclamp so the on end will be against the inner cylinder & the other part of clamp on the calipar housing or mount.. Force the cylinder into the caliper - opening it.. This way the new pads will get over the roter..
Put the calipers back on & sucure well..
Repeat in rear if has rear disc..