Drum brakes are not something I've ever enjoyed working on, especially since disk brakes are so much simpler to work on. But the good news is that since the rear brakes only provide 15-20% of the total braking force, they may still be just fine and not need new brake shoes. And to be sure, disk brakes use brake pads
to stop with, drum brakes use brake shoes
. That'll help you a little if you need any rear brake work done.