[Willowrun]

I had that same problem with a blazer before, though it was some years ago. Going by memory, with the tailgate open take the inner panel off so you can see what is going on in there. If you look in there at the channel you will see bolts coming in from the side of the tailgate (around where the support cables are) that connect the channel to the tailgate. Loosen those. The channel should now be able to be moved and adjusted. You need to use a long screwdriver or pry bar to carefully realign the window into the channel. You may need to loosen the other channel to get enough movement out of the window. Once the window is in the channel try to align the channels properly and tighten. You may need to raise the window out of the tailgate some during this process.