Changing rear brake pads
 

2003 350z. can the pads be removed without taking the calipers off the rotors, just by removing the pins?

Brembo? Yes.

not brembo

For non Brembo, you can just remove the lower slide pin and pivot the caliper around the upper slide pin to replace the pads, but you'll also need to push the piston back into the caliper for the new pads to fit.

dont forget to loosen the brake mc cap before compressing the piston

I assume you're referring to the filler in the engine compartment?

yessir