Rear disc brakes are similar to front disc brakes with one big exception. Rear disc brakes might house the mechanism for the parking brake. You can differentiate between the two types by inspecting the style of caliper piston it contains. If it's a hollow piston like a front caliper has, then it's likely that the parking brake mechanism is inside the hat of the rotor, separate from the caliper. If it's a solid piston with perhaps some grooves machined or cast into it, then your caliper likely has the parking brake assembly contained within it. You can also spot this type of caliper by looking for a parking brake cable attached to it.
If you see either of these things, you handle compressing the piston to accept the new pads a little differently. You can often use a special tool or equivalent to twist the piston back into its bore. Some calipers have access to a screw that needs to be turned in order to retract the caliper piston (some Mazdas come to mind). Check the service manual for your vehicle to see if that's the case with your vehicle. I still recommend opening the bleeder valve when compressing these pistons to avoid damage to the master cylinder. Here's a video on the process.