Help, windshield wiper arm removal

How do you remove the wiper arm on a 1987 suburban. I tried what my haines manual said to do, but no luck. Didn't want to force or pry.

I have a 99 and on that one you lift the arm and pull the tab out and the arm comes right off. The tab will not slide back the 1/4 of the inch with out the arm being lifted. I dont know if the 87 is the same. Dave

Try looking in the Tahoe, yukon and truck post for the 87 if your is diff for the 99. Dave