For drum brakes you need a hold down spring tool (or use pliers), a spring remover (on one end of the spring of the big spring pliers), a spring installation tool (one the other end of the spring of the big spring pliers). The absolute MUST have is a pair of needle nose locking pliers like a Vise Grip 7LN.
Not that I have done a lot of drum brakes in my life, but the one tool you might need (and several times I wish I had one) is a brake drum removal tool, like a NAPA SER 833 or a OTC 6980. It is possible to modify a typical 3 jaw gear puller to extend the grip range by replacing the following links with longer ones.