It's a self-adjusting mechanism, so just set it to minimum shoe diameter before fitting back into the drum and re-fitting the wheel. A couple of pushes on the brake pedal gets it back to where it should be. It would be handy to be able to release it before trying to get the brake out of the drum but this does tend to be a case of wiggling it till the shoes pass the lip that forms on the edge of the drum friction surface. It helps to clean this small lip off each time before re-assembly.
