You can just let them go on their own if you want to. They will only grow where they can get enough light.
I have used a pair of stainless steel scissors to remove mushrooms from a rock before but that always makes 2 of them if you leave any of the original one behind. If you must remove one from where it is you will have to remove all traces of it.
For example, I have a very large rock with 3 wonderful ricordia mushrooms on it. This rock also has 50-60 super fast growing
purple mushrooms on it. I want to make sure that the ricordia's have plenty of space to multiply so I cut off the caps of the neighboring purple mushrooms every few weeks to slow down their growth. I then let these removed caps attach to rubble and take them into my LFS for a discount.
If you cut a mushroom, make sure that you have some water circulation around it. They could turn to mush on you from a bacterial infection although I’ve never seen it happen.