The most obvious change you'll need to think about is widening your pf range as this is probably the greatest fundamental error made by FR regs making the transition to shorter handed play. Due to this 6m tends to play more aggressive than FR(at equivelant stakes), you will see more floats on both flop and turn so you'll need to use more selected aggression as you can't rep monsters as easy with a wider range. Best advice I can give is just just in and test the waters...my game of choice is $13 6m 18/12man and theres an abundance of fish at these tables. Good luck & hopefully see you at the tables