Rollback flash (Factory Stock) OF1 with Odin and attempt root with one or the other Yemen tools.
The first step should be straightforward; the 2nd seems to give mixed results. (Possibly because the exploit targets a race condition?)
If you look at those (Yemen root) threads, you'll note reports of 1st-pass success, and also reports by others claiming "wouldn't work in many attempts".
good luck
ps Theoretically there are other available (kernel?) exploits against the OB6 or OF1 that have never been tried, simply because folks give up trying after the first publicly-released root method is disclosed (e.g. Yemen). The bootloader firmware anti-rollback protection only prevents PL1 from rolling back to N* firmware; so if you don't want to use the Yemen tools (or can't get them to work properly), your only other option will be to start exploring and attempting to code up an exploit against OB6/OF1/PL1.
