You can get a boxed end wrench to break it loose, and a short socket w/a swivel extension on it to tighten it down when reinstalling. It takes a little work/patience and is a bit of a PITA, but it can be done w/o removing the caliper.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed