Just did that 2wks ago. Taking a deep breath, i'm holding up the whole diff with oil & driver side cv bolted on, figure 100lbs+, my buddy pulled out the driverside knuckle to aim the cv shaft in the bearing hole. Once the CV shaft is in the hole, i push up & forward so he can put the bolt through the flanges on the front x-member. Then push up more for the other 2 mounting points. Was a good workout of the day. + some mild back pain the next day lol... at least we had a lift for the truck...

91-22re(408xxxkm & counting with a rebuilt long block)- Flatbed/Camper
/33x10.5BFG-AT/Open 4:88/1.5"BJS/
+2"Shackles/Add-a-Leaf/AirLift/Dual-Batteries