In the absence of more informed reply, if as I assume you are referring to rear brake disc pads and then usually only if an electronic hand brake is fitted.
So far I have been lucky the only electronic handbrake rear brake pads I had to fit were on an VW Tiguan of one of my daughters and I was able to borrow a neighbours Scan Tool which after following it's instructions allowed me the retract the piston electronically, fit the new pads and then set it up again using the same tool.
Should be straight forward then, push pistons back fit new pads, check brake fluid reservoir and away.
You may have wear indicators to plug in, so apart from that just make sure good quality parts.
I've not done either front or rear pads on my 2015 500X (low mileage at less than 33K) but the fronts should be straight forward. For the rears then there are three options.
1) Manually release the EPB (electric parking brake). This may back the pads off sufficiently to allow new pads to be fitted. If not will/should allow the callipers to be removed for inspection. Just a matter of trying / playing to see the overall possibilities etc.
2) Use diagnostic kit to retract the calliper pistons for servicing
One could of course if no diag kit available go straight for 3) but 1) is a good place to start for general learning. I've often found that some official procedures are a little OTT and that playing and self learning and analysis leads to a better understanding, (even if it does not work out), than blindly following a guide.