nothing really, its supposed to be a direct bolt in swap
edit: now that i think about it, he'll probably need your whole rear end to make it work, or scrounge one up from a junkyard, because 8.8 gears and diff wont fit in an 7.5 housing, same with the axles, and he'll need to recalibrate his speedometer for the new gear.. sorry for the confusion
for a good swap all you really need is the 8.8 housing, the gears, diff, you can use the axles from your 7.5...you only need to recalibrate your speedo if your changing gear ratio...i think stock they are 3.15