If your brake pads are worn, you'll start hearing them moan or you will see the wear indicator disappear.
Some people use a tool to hone them again, some people use scotch brites. Some people just wash it with rotor cleaner. I cleaned the rotors with some simple green and scotch brite and beded them in according to my preferred method. If you dont clean your rotors your not going to get the pads to mate with the rotors and your brakes will feel like they don't even exist.
Step 1. Remove the 2 bolts and press the caliper against the rotor to compress the pistons, otherwise you wont be able to get them out. Read on and youll see what i mean.