hay here is the instructions on how i did that i just fixed my diff i was having the same problim this is how i fixed it
1st you know the nut for the slipper take it off that all you need to do with the slipper
2nd look on the right side were the shaft gose into the diff with those 2 slits are
3rd pop the ball cups off both sides just arthe shock tower
4th unscruew the ajustmen scrue for the diff un till that black thing on the left side will come out
5th see that nut in the senter get some thing that you can push thrue the backto get that nut out of the holder
6th replace that nut with the one from the slipper
7th replace the bad one on the slipper
8th it should be good thats the quick fix then when you go to your hobby shop bring the slipper nut and get as many as you need just get more than 1 hopw that helps