I just got back from a trip through the rockies, i live on a flat prairie my van has 156000km and is an 05. There started to be a sound from the right rear wheel, a grinding sound . I did stop and checked the wheel and brake and thought it was minor. As i got home it was worst so i removed the caliper and pads. I found the inner rear pad worn at the top and normal at the bottom, so i got new pads to install.
But you need a piston compression tool ($15) and you need to really turn hard cw to compress the piston, and the piston has 2 intends v shaped. Now remember this it will save you time. The v has to be paralell with the ground, so it will fit into the tang on the back of the pad. If it doesn't go on easy give the piston another full turn and it will go on.
The whole process is about 1.5 hours for both wheels and all you need is the compression tool, a 14 mm wrench\socket, a rubber mallet and a ratchet wrench with a 3" extension.
Once the wheel is off there are only 2 bolts to remove. It is a fairly simple job so do it yourself and save some bucks for the other problems. Oh one other thing if the rotor is damaged it is cheaper to replace it and you should use a coarse sand paper to ruff up the rotor surface while the caliper is off.