well, it your just replacing the pads you only have to take off one bolt and loosen the other one...
once the tire is off, take off one caliper bolt and loosen the other and flip the caliper up or down(depending on which bolt you took off and which you loosened)... take out the pads, then use a c clamp or brake piston tool to compress the piston so that the new pads will fit... then just put the caliper back and tighten up!