The best way to get rid of them is to get a peppermint shrimp. He'll eat it.
Cutting it won't do it. These guys are like weeds. Cutting it will actually help them spread faster.
I have fought these guys off and on since I set up my tank. The peppermints tend to leave one around, I guess to keep them for food. This doesn't bother me much as one isn't a nuisance but my last pep died and they are back in quantity. I also am slowly adding rock to my tank and one of my LFS has some nice rock but all of it is infested with these guys.
Anyway the peps are pretty cheap, stay out of the way and do a good job.
Another way is to take a syringe and inject the beast with Kalkwasser. This usually does the job as well, and can offer some satisfaction if you really hate these guys.