If it's still under your 36 month warranty, I'd let the dealer do it.
That way if there's ever something wrong it's documented...
They had to do mine as well. Mine was also off about an 1" from side to side. When I took the truck in, the service writer rolled her eyes when I told her that it was off some side to side. She indicated that it was a pretty common occurence...
cadman_ks