Howdy
Ed,
"
...How did it go?..."
I'm almost ashamed to admit that the whole thing went as
smooooth as silk!
But, as the head mechanic said (funny how the presence of a Hummer in a crowd tends to gather the gearheads...) "
Usually the anticipation of doing something, is more stressful than the actual DOING of something"
The DIY shop I went to was fabulous, and having the support at arms length was priceless even though I did all the work myself. Once I got it up on the lift I was entertained to see that the air bags were so completely deflated that they weren't even in contact with the lower seat (axle), but instead were all shriveled up and hangin' by the upper body mounts! Sheeeesh!
All in all, subtracting yakkity-yak time with the other mechanics, I think it took me all of 30-35 minutes. And that included removing the air compressor pan, tie wrapping up all the harnessess, and pulling all of the air lines.
OH!...almost forgot,
1) I didn't need to disconnect the battery cables to allow the system to 'reset'...everything just settled down all by itself with no 'air suspension' warnings.
And
2) I didn't have to remove the height level sensors either. Figured they weren't in my way, and it wasn't really worth the affort if it wasn't going to set off any alarm bells.
Next up, replacement of the driver's side rear window mechanism (recent break-in).
Can't tell ya all how GOOD it is to not be runnin' on the bump stops anymore!
Thanks again for all the sage advice, and the kind encouragement.
Warm regards,
Buck. 
PostScript: FYI, I tried to post a couple of photos, but for some reason I can't get ElcovaForum to accept the link addy....