Yeah your right, we're not a gear company, hard to compete with Genuine gear and 4 wheel parts/4wd hardware, they do huge number and have slim margins. Did they bother to give you good instructions with their gear set?
not with the G2's. the yukons usually come with a set of instructions though.
not really rocket science though. uninstall. add between .005 and .010 to the pinion shim, reinstall, check backlash and pattern (use a chart from randy's), uninstall, add crush sleeve, crush until correct preload, re-assemble everything.
on the lift took about 8 hours by myself. on the ground add a few hours. what took me the longest was things like getting the rear pinion out of the upper pinion bearing. i had to beat the piss out of it with a nylon hammer. took like 10 minutes of constant beating (hehehehehehe awesome), getting the rusty ass 13 mm 12 point bolts out for the unit bearings, same with the D44 retainer plate nuts. anywhere i couldn't get the impact into.
the rest of it is simple IMHO.
the poly setup kit would be ok if you get a set of free 4.10's or something and just need the shims/crush sleeve/etc and are trying to do it on the super cheap.
It just scares me re-using pinion bearings... more because i suck at not nubbing up the bearings with the bearing collar... and i don't know if you've tried to get axle parts for the JK at the local parts store... they seem to not be able to figure out WTF these axles are. nothing is ever right. pinion seals, pinion nuts, etc. nothing ever seems to be correct.