We found Yukon's instructions the most helpful. There was a decent amount of incorrect information online when I did my gear swap a year ago. Pentastar vs. non, 3.21s etc. as KB mentions. But that was over a year ago so that may have sorted itself out.
http://www.yukongear.com/Downloads/Manuals/Yukon_General_Installation_Instructions.pdf
There was another set of instructions I'll scan if I can dig them up.
Someone did mention- its a good idea to just plan on replacing bearings- at minimum be ready in case you need them. (Ie: Saturday at 6pm no one will have them.)
I expect your buddy has all this but this was our list of tools:
- Diff Spreader. Used to spread the diff. housing so you can remove the carrier (and add shims if needed). Alternative- crow bar and hammer. My husband made one for around $70. Cost on Amazon or Ebay: $170-$300. Try getting in a .0098 shim in (without bending it )with the use of a crow bar or screw driver and hammer. It can be done- but no way I'd do it. (I see Yukon sells one now)
- Bearing press. Remember the rear axle? It had to be removed and placed on a bearing press to get the pinion shaft out. And get the seized bearing off. Alternative: if you've hammered on the rear pinion for hours- not much. We bought a 12 ton shop press from Harbor Freight for $80. Look for coupons in any car magazine.
- Micrometer. To measure the shims. (Ours were not marked. )$30.
- A dial indicator to measure backlash with magnetic base ( base a must). $20-$40.
- Feeler gauge. We didn't need it- but chances are you will. $20
- Bearing puller (clam shell style). $150-$200. Highly recommend. If you mess up the bearings the old fashioned way- replacement bearings are $100 plus per axle.
- 1 5/16" socket & 1 1/8" sockets (1/2" or 3/4" drive). With big ass breaker bar or impact wrench.
- Slide hammer. Useful but not necessary. Had one- don't know cost.
- Dead blow hammer.
- Digital caliper up to 6". $10.
- Bench vice up to 6" will simplify the process a lot,
- Hub tool. CRITICAL. $20. Locks the drive shaft input flange in place while you crank on the pinion nut with above referenced bad a** breaker bar or impact wrench.
- Your local shop- for anything you weren't expecting.
Some of that list may be off a little- I am merely the shop wench, tool hander and tiny handed assistant.