I checked the CSM, the ASM and the BSM, and couldn't find anything on removing the 1/4 panel extensions on my '72 Supreme. So, here's my question...can they be removed without dropping the rear bumper?

 

No

 

if you remove the rubber filler first, you should be able to get the extension out, Unless the gap at the bumper is very tight Tim

 

If you're talking about the gap between the extension and bumper, it's pretty close to factory specs.

 

Mine is at spec and I got mine out to re do the end chrome pieces and put in new rubbers Tim

 

That's what I wanna do. Was it a PIA to remove them without dropping the bumper?

 

I only need to replace the passenger side trim piece, so can I just loosen up the bumper on that side to lower it, or do I need to loosen up both sides?

 

Just a guess on my part but I'm going to say no you can't just loosen the bumper on the passenger side (without involving some grief). When I have to work on bumper components (brackets, bolts, alignment and the like) I find one or two methods are simplest:

(1) Using an engine hoist/lift. Loosen all bumper nuts, bolts, etc. from ensuing brackets & hardware. Wrap bumper in a blanket, towels, etc. Use some blue painters tape on select nuisance areas. Create a ratchet or rope sling & remove the bumper - you can let the bumper just hang in the air or whatever. This method works well for reassembly making the sling easy to navigate bumper back into position while securing hardware; or,

(2) A large floor jack (or two). Same as number (1) above. Loosen, brackets & h/w, wrap bumper. You can use a block of wood or wrap the floor jack cradle with a towel(s), etc. then position floor jack at a leveling center position. I've placed jack stands in strategic locations for bracing, as well. Some jack stands work better than others - I own four different sized sets (x2) of jack stands. At any rate, you get the idea.

Bottom line, IMO, it's far easier to maneuver when you have "space" than not to have space to work w/ freedom. Good luck.