This toadstool is getting too big for it's spot. I want to get trod of one but I'm unsure of how to cut it. I don't care if one dies but I don't want to kill them both.
Wrap a rubber band around the area it 'Y's' at. Use a frag tile and they'll both settle onto it. As the pressure from the rubber band pulls, it will cause the trunk to naturally split.
Use a new razor blade and cut in one motion right here. This will give you two good stalks and its already attached to rocks or a plug. Run heavy activated carbon.