They are a bit more difficult to replace then disc brakes, on the average. It requires removing strong springs, and clips, and also trying to keep the brake cups on, which tend to push out and fall out. Usually, though, brake cups should be replaced anyway, since they are old also. Then, removing the shoes, and trying to remember which one goes on which side, (one shoe is shorter then the other) If the brake drums are scored badly, that is if they have deep ridges in them, you will have to take them and have them ground down. Putting shoes on a scored drum is not good, they will wear fast and maybe not work as well, either. Oh, I forget, just getting the brake drums off, can be a real pain, Sometime, you have to loosen the brakes manually, so that the drum can come off. And if replacing the cup,s you will loose brake fluid, so then you will have to bleed the brakes after you are done. Replacing the shoes and trying to put the springs on with pliers can sometimes cause bleeding hands and fingers as the springs slip.( There is a special tool for the springs, so you won't have to use pliers and bang up your hands) Then once you get the shoes on and in place, after dropping the shoes and other parts on the ground three or four times, you finally put the drum back on and now, you need to re adjust the brakes against the drum. And finally, you bleed the brakes.