You can adjust the shoes out a little with the drum off. Just leave them just loose enough to still be able to slide the drums on. Then drive backwards sort of fast and pull the emergency brake. A few times of this and your rear brakes should be nice and tight. It works for me anyway.

PS - If you have installed new brakes shoes you will need to first lift the center console cover around the e-brake and back off all the way on the adjustment there. Do this before adjusting anything else.