i just bought a fbody calipers from a 99 camaro and wondering if it's good idea that i should get a piston rebuild kit for it? can someone give a a direction how to pull out the old pistons and reinstall new one?

This should help: Brake Caliper Rebuild
And since you are rebuilding you might as well take the time getting them powder coated as well!

thanks monteman for the link. i wonder if you don't have shop compressor air hose, what can you use?

...an air compressor and a duster nozzle.

Only safe way to remove the pistons from the caliper. Use a block of wood as a pillow for them when they do shoot out, and watch your fingers.

If you bought them used..couldn't hurt to freshen them up now with some new parts before they go on.

~F~