If it's that high because you didn't add any top off water for the 2 months, it'll probably be ok. If you did something to make it skyrocket in a day or something, probably not.
Test the water for ammonia. If you don't have any over the course of lowering the salinity, you're all set. If you do have ammonia, you need to continue letting it cure until you don't. Probably killed much of the life on it, I would think, but live rock's never truly "ruined" unless you contaminate it with some kind of poison. You can always replace the critters.