Replace with 6". Should give you enough room to demo the 4" stuff.
Still a pain though.
So they got these 4" cans that have ballasts on the box plate with 1-4 romex in each can. They want to change to LED. I can barely fit my fat hands in the tiny holes. I think these may bid out at 20 minutes each to take out old can, remove ballast from wiring, add the new can with the whip and close up.
I looked at other ways to do it, but only drywall breaking will speed me up, so far as I can find. Any other ideas?