Rear Brake Job, with the Kent Moore Tool

here we have the caliper un-mounted from it's normal place and bolted in place using the top part of the caliper's guide and bolted into the bottom hole of the brake adapter bracket. This way you will be supporting the caliper while you compress the piston in to place.  When you are moving the caliper, make sure that the pipeline to the caliper does not get bent too much.
Here we have placed the socket of the KM tool over the piston, and the compression guide into place in the socket and with the back plate inside the caliper ready for compressing.
Here is another view of the right rear caliper from the rear.
Again, something, but from the front.
With a ratchet, turn the center post clockwise while holing the larger portion of the KM tool. You will be able to turn the piston all the way down until it has bottomed out.  The turn the larger portion of the KM tool clockwise to loosen up and remove tool. That completes the compression of the rear caliper. 
Then remove the bolt and place the pads in the brake adapter braket, putting the larger of the two pads on the side with the piston.  Apply lock tight to the the tapped holes of the adapter, and secure yoke and caliper to adapter.  Tighten capscrews to 30-40 lb-ft.   and don't ask how your torque the top bolt, it's a bear to get too!

Make sure the brake lines are clear of the rotor after you have mounted the calipers and completed the job.

Check you brake fluid levels for proper level.

I personally would check your pads about every 12,000 miles,   Rear pad should last up to 15,000, while the front can go as long as 25,000 miles. Now depending on what pads you install, life span of the pads will be different. Cheaper, softer pads will have more stopping power, but may fad as they get hot.  While higher costing pad like Kevlar pads, will require more braking power to stop, but will last longer. I like to be in between, with a medium rated pad, and willing to change the pads more frequently, and to have better stopping power then the higher costing pads.  The NAPA MES-7122A-M. is about $40 for a set the will do the front or the rear brakes.