Do i need to change the brake pads and discs???

SOURCE: How do you compress rear brake caliper?

Dear Sir/madam,

The pistons on the rear brake calipers SCREW in to the caliper. There are notches on the inner edge of the piston face. engage the notches with a large needle nose plier or a large flat washer and turn clockwise (as you face the piston) to turn the piston in.
There is a special tool that is available at your local autoparts store that is absolutely necessary and will save you a ton of time and aggravation. Using a needle nose plier or washer does not allow you to apply enough pressure unless your are the incredible hulk.

thanks
Good luck

SOURCE: Rear disc brakes drag after installing new pads

Did you Compress the Cylinders in as far as they would go when Replacing the Pads.? If not, Depress the Caliper Cylinders Back into the Caliper and install back Loose. Then Bleed the System. When you get in and Press the Brake Pedal a Few times it will set these to where they need to be.

SOURCE: Rear Brakes on a 2002 GMC 2500HD.??

You will need a large allen socket or torqes (sp?) socket to loosen the caliper bolts; you can get at auto parts places. Other than that you will likely need a medium to large deep throat C clamp to force the fluid back to the resevoir by squeezing the calipers back in the body. Do this slowly as there may be check valves to over come with the fluid return. I am not aware of other special stuff.

SOURCE: i'm changing my brake pads and discs,but my discs are rusted on

You use a 2x4 with small sledge,or a plastic heavyweight hammer
like mechanics use and do what Emission said. If you soak it make sure its free of this oil when it goes back on,and that no oil will drip from assembly when it goes back on. Beating the disk has always come off with the right hammer without oil.

SOURCE: change rear brake pads?

If you have done the front, the back should be the same, if you have all wheel disc brakes. If you have drum brakes, then it's a bit different, but not too hard. Let me know if you have Drum Brakes in the back. When it comes to drum brakes, it's best to use a book with written and visual directions. I promise it's not as hard as it looks. Once you've done one side you'll see how less complicated it really is, compared to how it looks. If you can, purchase a book ( I prefer a CHILTONS) as it is more descriptive in directions. If you cannot, let me know and I will do my best to walk you through it. I will also look online and give you the URL.