How to remove the big green hairy mushrooms from the rock and attach them to a new, small rock?

I was told to cut it off by single smooth movement with a new razor blade. And attach as usual mushrooms.

Tried, disaster:

1. Cutting off anything by razor blade far in tank, without seeing what you are doing is not a good idea, even with half of razor blade (fingers).

2. The rock was uneven, mushroom migrated to a concavity. Spoon-shaped blade would be much better!

3. I wasn't able to cut with smooth movement through a couple of inches of the meaty mushroom's base. It was a butchery, needless to say. Same was with cutting them in quarters for propagation.

The poor mushrooms didn't recovered after that, decomposed in Q tank, even with water changes, filtration and carbon (but no spare small skimmer).

New mushrooms started to grow on the old place. I have to be prepared to the next removal, with better results.

How you removed your big mushrooms (~5" the opened mushroom diameter, ~2" diameter of its base, or more)?