Not as far as I know
because you have to remove the left shift rail far enough (forward) to clear the pill for removal which also requires removing the roll pin in that same rail for the shift fork. I don't think there is enough clearance in there for the shift rail to pull out that far if it is still in the truck. Be sure that the left rail is also clearanced at the front tip so it won't hit the adapter case or shift rail in the front case or you'll have problems there as well. I had a small issue with my 2/4 shift rail hitting the inside of my adapter case
which I was able to fix without too much difficulty after removing the rear case.
Did you install the twin stick yourself? Did you not do this part when it was done, perhaps? This sounds like what you're having problems with.
Plus it's much easier to do on the bench than in the truck. Especially if you happen to drop the roll pin in the case.
Good luck with fixing it.