I think you should be able to get the ones off the smooth rock at the bottom with relative ease, by taking the rock out of the tank and putting it into a separate container of tank water, then when they close up, use a plastic straight edge of some sort to *really* carefully scrape/lift the foot off the rock.
The tricky part (for me, always) is reattaching them. If you try and glue them directly, they’ll slime up and won’t stick. I usually get a shallow dish of some kind and put a bunch of rubble in it, then place the mushroom(s) face up on the rubble. If you’re able to keep the container somewhere that will keep the water reasonably warm, such as inside a bigger container of water (about a gallon) that you can keep warm with a betta heater (the really tiny ones) and then gently stir the water in the big container every couple of hours for a few days, the mushrooms should attach themselves to pieces of rubble. If the stirring is too vigorous the mushrooms might float away but if you’re careful not to disturb them too much, they should stay put. It’s easy to check on them by just moving the shallow dish gently to see if they’re attached yet. You can then glue the rubble where you want it.
For the ones up on the rockscape, I don’t think there’s a way to get them off without damaging them. What I’d do if it were me, is try and find a way to shade them so they move to find light. If you strategically place some rubble near them, they might crawl onto it - or not.
DISCLAIMER - Lol! I always have problems with mushrooms walking off their rocks and then have a heck of a time sticking them down again. Sigh.
