I used a paper clip in the small hole in the lock cylinder. You will also need your key in the lock cylinder. Easier if you take the door off first. You should lock it with the key then the tabs inside the lock cylinder all line up with the hole. You have to push down each tab, pull the lock...
My monte was conveted to 134a by previous owner. It pretty much sucks during the summer. I can barley feel the cool air. During winter its cold at night tho LoL.
I live in Mesa and I go to ArizonaGn, even if I have to push it. The shops think they know about Turbo Buicks, but they only know what they read in their shop manuals.