S-Off Evo 4G LTE

So I have an HTC Evo 4G LTE that I'm working on, and I upgraded Hboot to version 2.10. That probably wasn't quite as brilliant of an idea as I thought, being as now I can't seem to gain S-Off. I know how to get S-Off on Hboot version 2.09, but when I ran the RUU which included that, it gave me the error "ERROR : BOOTLOADER VERSION ERROR," so I figure it doesn't want to *downgrade* anything. Can I get back to Hboot 2.09, or gain S-Off some other way?