Just upload any 3.7.x style click the ignore box, you might then have a box at the top of main admincp page saying "you have out of date templates" (or something like that) take alook and make the minor adjustments needed. (be carefull if just reverting)
OR
Update to latest version.
OR
Wait till gold version comes out as thats what most designers are waiting for till they update their styles,
vB say that rc3 should be the last rc and so the next release will be Gold which to be honest shouldnt be to long.