Rear drum brake change

Drum brakes have been around since the first cars. There are plenty of resources online on how to replace the shoes. Check out youtube. I know the Mariner used drum brakes, make sure your vehicle has them vs a brake rotor and caliper. The actual drums rarely need changing. Just change the shoes and springs. Sometimes the wheel cylinders need replacing as the tend to leak over time. If you never did this work before, have a garage take care of this for you. With brakes you want to get the work done right due to safety.

You should get new drums or get the old resurfaced to lessen the chance of squealing sounds