Just a note..... I had seen several threads about these bolts being quite the PITA.
After 3 hours and a trip to the tool store (O'Reillys had it), got the four T55 bolts holding my "PO wrecked bumper" loose and out.
Technique was simple.......spray liberally with KROIL (Love this stuff). Pound liberally with machine hammer.
Curse VERY liberally about the engineers at Jeep placing the lower T55 bolts too close to the spring suspension to get my 3/8" T55 + 1/2" adapter into the space.
Drive quickly to town (15+ miles), and spend liberally for 1/2" drive T55.
Remove remaining two T55.
Bumper on ground.
Only broke ONE of them off
, drilled it out, chiseled out remaining bolt.
Ya gotta love working on a JEEP
......or paying someone else
to do it.....