1) have someone hold the wrench in place, then hammer it to right direction. (which is right to left)

2) what ever fits right.

3) Make sure you go get some break cleaner, just spray througly to get ride of the break dust before you work on it. NOTE AGAiN..BEFORE. Be sure to push the pistons back on the caliper if you are planning to change the pads with C-clamps. torque for the bolts that holds the caliper in place? just tighten it. it's just there to hold it in place.