1996 drum brakes

[dallas2]

I am attempting my first GMC rear brake job and cannot get the rear drum off. I have been a ford owner in the past and am not familiar with how to access the auto adjuster to slacken the pads. My chiltons says to insert a rod into the access hole and "push the parking brake lever off its stop". I did so and can't tell that it helped in any way. My truck is a 1996 GMC 1500. Kinda embarassed about this as I've been working on my fords for a couple of decades.