I had one installed on Saturday and had replacement 4.11 diff centers put in at the same time. I got to the mechanic at 7 and was gone by 1 and that was putting the back center in also. Didn't look like a complicated task and if I hadn't just had a hernia op I would probably give it a go. The rattle gun certainly made a difference.
I'm yet to test it but have been told to just take it easy until you get use to it.