All credit is to element6968 and lstrike from MicroRCcenter.com.
And pics.
1 cut the tabs that stop from any further ariculation.

here them cut off

2 Next with the rear end seperated from the truck you will have to cut the corners of the squared portion that fits into the grove when the rear end is attached. It is below the circular area that houses that shaft for the AWD. This piece in conjunction with the tabs are what stops the car from the factor from any further articulation. If you look at what I have cut off essentially it will allow the rear end to twist slightly passed where the tab used to be

One's you have it all smoothed out. I sliced off a small triangle (remember sometimes less is more be careful little by little) then just sand it down a little bit.
3 well theres not really a 3 put it back together and bam! normaly you will need a body lift or new one.