How do I replace the front rotors on my truck it is a 4 wheel drive.

1. Raise vehicle
2. Support on jack stand
3. Remove lug nuts
4. Remove wheel
5. Remove bolts holding caliper
6. Remove calipers
7. Remove brake pads
8. Push piston into caliper
9. Inspection rotor for damage if damaged replace
10. Install new pads
11a. Replace caliper on rotor
11 b. Replace bolts in caliper and tighten
12. Bleed brakes
13. Replace wheel
14. Replace lug nuts
15. Lower vehicle
16. Tighten lug nuts
17. Test drive vehicle

This video should help. It's a 2000 Silverado but is probably the same as yours.
2000 Chevy Silverado 1500 front brake pads rotors replace

it is a one peace unit all you had to to is re place the barrings and check the races if the races are bad you need to buy the rotor and hub

Front (4 Wheel Drive) To Remove:

1. Raise and support the vehicle
2. Remove or disconnect the following:
   • Tire and wheel assembly
   • Rotor (See: Disc Brake Rotor)
   • Wheel speed sensor and brake hose mounting bracket bolt from the steering knuckle
   • Electrical connection for the wheel speed sensor
   • Front drive halfshaft assembly (See: Halfshaft)
   • Hub and bearing assembly mounting bolts 4WD front hub
     
     
   • Hub and bearing assembly

To Install:

1. Clean all corrosion or contaminates from the steering knuckle bore and the hub and bearing assembly
2. Lubricate the steering knuckle bore with wheel bearing grease or the equivalent
3. Install or connect the following:
   • Hub and bearing assembly
   • Hub and bearing assembly mounting bolts and tighten the hub to knuckle bolts; Torque to: 133 ft. lbs. (180 Nm)
   • Front drive halfshaft assembly (See: Halfshaft)
   • Electrical connection for the wheel speed sensor
   • Wheel speed sensor and brake hose mounting bracket bolt to the steering knuckle and tighten the bolt; Torque to: 106 inch. lbs. (12 Nm)
   • Rotor (See: Disc Brake Rotor
   • Tire and wheel assembly
   Wheel lug nut tightening sequence
   
   
4. Torque the lug nuts to specification
5. Test drive the vehicle to confirm the repairs

You will have to remove the front wheel bearing's, due to the brake rotor bolt's to the hub.

you need to disassemble the four wheel drive unit then unbolt the rotor from the hub

I am not an expert but yes i beleive you have to remove hub nut to get rotor off,also will need flat head screwdriver to unscrew internal nut before bearing.I also changed bearings while i had it all loose.

Bad news... It sounds like you have a broken/stripped axle. I would start at the wheel and start disassembling from the outside in. It may just be a stripped spline in the spindle.

The rotor and hub assembly are held together by the studs,you must first remove the 4-wheel drive hub assembly,then the wheel bearing nuts,and pull the hub and rotor off as a unit. Next lay it(back down) on a piece of wood, using a drift punch drive the studs out. Turn it over ,lay it(face down) on a block of wood, line the new stud splines up with the grooves in the hub and drive them in with the punch and reassemble. A set of dentist style picks will be helpful with the clip in the 4wd hub and a 4 lug 4wd nut wrench will be needed.

Remove caliper and nut to axle should come of with a little help of a rubber hammer. Knock bolts out from the front and drive new ones in from the back. You can use a lugnut with the flat side down to help pull them in and a hammer to help. Hope this helps.