I fragged my toad a couple weeks ago, and the pieces are already attached to frag plugs and doing great.
It's pretty easy, really.
1. I used a large bowl. Take a piece out of the tank that you want to frag.
2. Using very sharp scissors, cut around the stalk whatever you want to frag, just make sure not to cut the stalk. I only cut a small piece off my leather, but really you can cut a whole side off, without hurting he stalk.
3. Now that you have the section you want to frag removed from the mother, cut it into as many smaller pieces as you want (well, not too small of course.)
4. Rubber-band the frags to frag plugs, and place them somewhere where they can safely heal (my cleaner tried to attack my new frag, so watch out for things like that.)
5. The mother colony should heal up pretty fast, but still, watch out for infections (from what I've read this is rare.)
The new frags should attach quickly, at which point you can remove the rubberband.