The only tool you need other than hand tools and a snap ring pliers is the tool to tighten the metal band, it runs about $12 at Napa. It doesn't take that long to pull one apart and put on a new boot, which w/tool should run you under $25 to do. You could also replace the boot w/o removal of the cv by buying a split boot(or whatever it is called).

I don't think duct tape is going to work, but you could try stitching the tear back together w/fishing line, and seal it w/some rubber sealant.

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