If you do not have a lift or lube pit to work under then I would suggest you jack it up and pu jack stands under all four corners to keep the rear axle true to the frame and give you the clearance you need to get under the truck. Once you have it installed keep the drive shaft engaged untill you get the vehicle back on the ground completely, then disengage and test for proper operation. Good luck and enjoy!
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7