You have to remove the caliper completely except the brake lines. Then the pads will slide in a groove on each side of your rotor. Then you should be able to reinstall your calipers and that should take care of it.
Front brakes are done the usual way but the back pistons have to be screwed into the calibers not pushed in.
Brake calibers can be rebuilt, but my advice is to just replace it with a new one. Be aware that if one is sticking then more than likely your brake fluid has become contaminate with moisture. I would replace both calibers and not just one. Remove all the old brake fluid and install fresh fluid from an unopened can.
The center brake light replacement will require replacing the entire brake light assembly. Remove the wiring harness. Remove the center brake light retaining screws. Reverse the process to install the new center brake light.
On the back calibers you have to screw the pistons in they don't compress in, you can ruin them if you try. They sell the square tool for a couple of bucks.
Sticking caliber. Flush the brake system and install fresh brake fluid, then bleed the brakes. If that does not help, replace both calibers and brake pads on the axle where the brakes are grabbing.
If you change the brake fluid every 50,000 miles the calibers will last the life of the vehicle.
The park brake on my 2004 LS is in the center console below the shifter and is an electronic lever.
How to Install Front Brake Pads Check Related Links Below
you will have to get a brake caliper tool. the rear caliper the center part turn or screws in with this tool
The 1998 Nissan center brake light is a sealed unit. The entire brake light unit will need to be replaced. Remove the wiring harness. Remove the brake light retaining screws. Reverse the process to install the new brake light unit.
Corroded calibers that are rusting and sticking. Moisture is in the brake fluid. Replace the calibers and replace all the brake fluid. It can also be a sticking slide pin on the brake assembly. Check that before replacing the caliber.
If u are talking brake rotors remove the calibers and the calibers support the rotor should almost fall off in your hand