First measure the interior diameter of the drum and manually rotate the star wheel until the shoes are within a quarter inch of the inner drum diameter. A brake gauge is very helpful but not necessary.
That step isn't necessary, but it reduces the number of stops you have to do in the next step.
Drive vehicle and make one forward stop followed by one reverse stop. Repeat procedure 8-10 times making sure to come to a complete stop each time, a rolling stop won't activate the adjusters.