Brakes Cant get the disc pad housing off to change the rotors

Remove the wheel---undo the bolts that attach the caliper to the steering suspension . Lift the caliper off the disc rotor.--remove the outer pad-- Using a G clamp push the inner pad and piston back into the caliper housing. This is best done by opening the bleed screw first so that the oil flows out and not back to the reservoir. Check that the caliper body slides freely on the mounting pins, Fit the new pads and all shims as they came out. Refit the calipers to the mounts and re-tension the bolts very tight. pump the brake pedal several times to take up the adjustment and then bleed the brakes to remove any air in the system. Any damaged disc rotors that need machining or replacing have to be done as a pair and any pads will have to be replace on both sides to maintain even braking

On some of the Toyotas, the brake pad info that some auto parts places have on file is incorrect. The pads are just slightly too big and the are touching the un-worn part of the rotor, making a noise that almost mimics the grinding sound like when a pad is completely worn to the metal/rivets. Sometimes it even causes noise when the brakes are not being applied. This is often visible on the rotor- the ridge where the original pad ended, is now a clean bump instead of a ridge that is very rusty.
In some cases, this noise will clear itself as the rotor clears and the pad wears. It's always possible that the pads that were changed were 'cheapies' that were a bit undersized. The only solutions in that case are get the same kind again, or, turn or replace the rotors.

are you saying that the brake calliper body has the special bolts holding it to the axle housing that you cannot undo and you cannot move the callipers back off the discs to get the discs off
to get the correct tool to do the job , ask a brake specialist shop for the tool size

How to change front brake pads & rotors (brake disc) on 2006 Audi A6:

Atention!!!
Don't disconnect any brake line from caliper!
Don't disconnect any ABS sensor!
For change front brake pads you must raise vehicle, remove wheels, extract the retaining spring of the caliper, and remove the caliper as follow:
1. Do not disconnect the brake hose from the caliper, and do not allow the caliper to hang by the brake hose!
2. Remove top and bottom caps (on back side of the caliper) for access to guide pins, then unbolt and remove them from the brake carrier. Remove the caliper.
3. Now you must thoroughly clean the brake calipers (free of grease).
4. Remove outer brake pad from brake carrier.
5. Pull inner brake pad out of brake caliper piston.
6. Remove brake carrier from wheel bearing housing (two ribbed bolts). 125 Nm
7. Remove brake disc from wheel hub.
8. Install brake carrier on wheel bearing housing. Tightening torque for two ribbed bolts = 125 Nm.
9. Check up the brake fluid level on the reservor, and emptying if neccessary!
10. Push piston back into brake caliper housing.
11. Install inner brake pad (with expanding spring) in brake caliper piston. (Arrow marked on pad - if exist, must point in direction of brake disc rotation when vehicle is moving forward).
12. Install outer brake pad into brake carrier.
13. Bolt brake caliper housing to brake carrier using two guide pins. Tightening torque is 25 Nm.
14. Install both caps.
15. Insert retaining spring into brake caliper housing. Important: Depress the brake pedal firmly several times while the car is stationary so that the brake pads adjust to their normal operating positions!!! Check brake fluid level and top up if neccessary!!!

Normally a "pulsing" brake pedal means that that you have a warped brake rotor or the brake caliper is lose. I would start by taking the front wheel off and inspecting the brake pads and the rotor. If the brake pads are worn down bad replace them. Pay special attention to the brake rotors also as if the are grooved very bad, they should also be replaced.

Now, did the mechanic even suggested anything about MACHiNiNG ur ROTOR brake disc before putting those brake pads? U got UNEVEN brake disc and needs MACHiNiNG to equally level the pads grip to the rotor! Do it i'm very sure of it! Taaah!

Disk's and pads are the same thing,Brake pads,Brake disk.
Are you meaning the rotor?
If you are the answer is yes,you don't have to replace the rotors unless you have a rotor brake vibration when you are applying the brakes on your car.
If you do want to change rotors later,you can but remember to take sand paper to the previous new pads,because they were used and got hot and hard they will now score the new rotors,that is why you sand the pads.

That's to be expected and is completely normal.

Rear brake shoes as fitted to drum brakes can typically last up to 60k miles with periodic adjustments, but you have rear disc brakes and the shoes will typically last half of that.

Also, modern brake pads no longer contain asbestos and are now made using harder metallic compounds; the direct result is that brake discs (US=rotors) are also considered to be consumable items as they are worn down by the harder pads. It's not unusual to have to replace front discs every other pad change and rear ones with every pad change; in both cases the mileage will typically be around 30k miles on most models.

Parking brake is operated by a cable and not the caliper. Your car has disc brake pads for squeezing the rotor to stop, the parking brake has drum type brake shoes that push out on the inside of the rotor. Changing the disc pads only requires squeezing the piston back in like usual.

No you don't, you can have them turn the brake disk/rotor . Turning the brake disk/rotor is when you have the surface of the disk resurfaced by having a brake lath cut the high spots down. The disk are cheap enough now that most will just replace the disk/rotor the same time they replace the brake pads. You can pick up performance drilled or slotted brake disk/rotor for almost the same price as the OEM disk/rotor. Good luck and hope this helps, you can pick up the slotted brake disk/rotor at Auto Zone for a reasonable price and they will have the step by step instruction replacing the disk and if you like to just have the disk/rotor turned, they can do they there too.