Get yourself a small tupperware bowl (depending on the sizes of the mushrooms), put a bunch of rubble rock in the bottom, put the mushrooms in and cover it with mesh & rubber band, then set it down on the sand bed in a lower flow location so they're not constantly blowing around in the current. Their feet will eventually latch onto a piece of rubble that you can glue to a larger chunk of rock...
Don't try to glue mushrooms, it doesn't work. When irritated, they generate a slime coat that prevents adhesion, and they will just drift away... they have to attach themselves. Usually takes a week or two for them to get a solid foothold, depending on any damage from removal or fragging.
