Polyps and Waving Hands outgrowing home

My polyps and waving hands have grown or are growing beyond the scope of their rocky home. I've noticed they are creating a plate to move onto, but honestly thats just going to hit another rock that's full of corals.

I know I need to cut them back, but I'm scared. And they aren't just like cut the bottoms and snip snip..if it were you what would you do, and what do I do with the cuttings..I can grow waving hands 4 inchs by 4 inches every 2 weeks..the green polyps are slower only grow in diameter an inch across in 2 weeks...these polyps are about a 12 inches across...waving hands are about 10 inches long and only 6 inches deep, stand about 4 inches tall..the pulsing xenia was one branch but now its like 4 and measures about 8 inches long or longer..

If the picture upload doesn't work please look at my gallery

 

love waving hands! but for some reason mine crashed after thriving and spreading for 8 months and after that i could no longer grow them

 

heh, I let them grow, and then I trade them off to several LFS', but, that's just me- give it a try. I think I have more colony's of purple anthelia of mine around town then any other coral on the market in my local area- I grow them to be very hardy.