How many montis, what size, and how much money have you spent on them?
If you have a small collection, easiest is pull them. There's a lot of cool corals you can do instead.
Alternatively you could try some experiments. Coral don't necessarily care about being on a nice rock. Light and water and they can be good to go.
MEN(udis) I don't believe hang out on the main part of the flesh. They're either on the edge, or have eaten a line into the flesh. That means if you break off healthy tissue, they likely aren't on that.
In my experience that really helps get root them out. Pop them of the plugs, toss the plugs in RODI to clean them, and attach to a new plug, covering the non alive section (and some of the alive) with superglue.
If you wanted to do an experiment, what I'd try is do that, but instead of attaching to a plug, attach to some fishing line. Then attach the fishing line to something on the top of the tank to hang the corals. They do that in ocean growing setups, and I've seen it a bit in tanks. It'd be interesting to see if a MEN could get to them. My guess would be no. It'd be a really interesting test.
Regarding them in the rest of the tank, you're probably screwed. Again, I know the infestation term might seem off, but they aren't going to be climbing around the glass as adults if you've only got a couple. At this point you've got a MEN problem, so I'd make your decision accordingly.
I have a huge amount of green spongodes you can have from my frag tank that has had a MEN problem
. I don't do coral swaps now to avoid ever giving anyone anything. I had much higher success after I cut down all my colonies and rooted out dead tissue (finding a lot more I couldn't otherwise see). My wrasses have I think put everything under control.