I use a spanner wrench to adjust the hex in the lower control arm. If the indexing on the bar is correct you usually only need to twist the hex a little bit to get things to line up. I just built a simple spanner wrench that fits into the hex so I can easily twist it into alignment.

I will say that some of the torsion bar vendors don't seem to understand indexing. I've see a few bars that cannot be installed because the hex ends aren't where they need to be. If the ends aren't indexed correctly (function of car weight, ride height and bar stiffness) then you'll never get it installed.