Replacing the parts of a Drum Brake
You will need a long spring tool and possibly a primary spring bolt removal tool.
Lift the vehicle with a jack and take the wheel off. Remove the drum by pulling it off directly, or taking the keeper screw out first. Check the inside of the drum for pitting and debris and stuff, and check the brake's innards for leaks...especially around the wheel cylinder where those leaks might happen. Remove the shoes by levering off the long retainer springs and then turning the center primary keeper spring in the center of each shoe. The shoe will pull directly out.
Resurface the drum and replace the shoes with new units. Replacement of the wheel cylinder involves turning the mount screws counterclockwise, then pulling the main wheel cylinder piston out. There are three gaskets on most wheel cylinders that can be replaced easily. The adjustment bolt at the bottom of most brakes will need a little play to operate effectively, turn it clockwise until it is just a bit off of snug.
Many people make it sound and look harder than it really is. Once you get into the brake, you see how it operates and what goes where.