Without knowing why you want them off of the rock, you can take a clean new one-sided razor blade and cut them off. You then can put them on the sandbed or in a glass or glass bowl that has some of your live sand in it and place it back in your tank. They usually take a week or two to get the sand to stick to them. After they have the sand/substrate stuck to them you can then remove them and place on a paper towel to dry, then put a little instant glue gel on the sand that's attached then place on a rock in your tank, holding it in place for 15-30 seconds. This won't be easy because they are slippery but it can be done. Oh yeah, you should wear gloves for this. Hope this is what you were asking for!