It is a breeze. I just put a Durablue axle in, and while I did it, I took off the bumper, A and D arms and swingarm and had the whole lot powder coated.
Real easy to replace the bearings in the axle carrier, all sealed. Buy from a bearing shop, not the dealer. Only about $8 for both, plus the seals. Pack it with loads of grease and you are away.
The after market axle has much better mechanism and you should go wider, while U r at it.
I also re galvanised all the bushed covers etc, so it is looking quite trick.
Not a hard job. Want to do the frame next. Thats a bit more work.
Cheers, Percy