Rear brake shoes brake pedal becomes hard?

Here is a guide that will help give the steps needed to complete this however, you do not have shoes and drums on this vehicle.

This vehicle has pads and rotors on the rear so here is the info that will help with this:

https://www.2carpros.com/articles/how-to-replace-rear-brake-pads-and-rotors

You do have parking shoes so here is a guide that will help with this as well:

https://www.2carpros.com/articles/parking-brake-shoe-replacement

Also, this video will show how to retract the rear piston:

https://www.youtube.com/watch?v=j8YwfSKEzZo&t=29s

Below is the process from the manual that will give the detail that you will need on your specific vehicle. Let us know if you have other questions. Thanks