Most of the time, the drums have a ridge worn on them that will keep you from either installing or removing the drum once the shoes are adjusted for full contact. The exception is to have the drums turned to clean them up and remove the ridge.
Normal procedure is to install the drums and adjust the brakes via the small hole in the backing plate by the adjuster wheel. Instal all the parts, and bolt the wheel on. With the trans in neutral, turn the wheel and work the adjuster. When you feel a slight drag, you are good to go. The shoes will wear in and the drag will be gone after a short drive.
Most of the time just backing up down the street and applying the brakes several times will get them adjusted sufficently.