How do I get it out?

[canadawest]

If the brain is in fact regenerating, I would just leave the polyp. In time the brain's tissue will sting and irritate the polyp and cause it to release it's hold, or die.

Now this is just an assumption as obviously I'm not a marine biologist, but it has been my observation that LPS coral tissue is quite agressive and that polyp probably doesn't stand a chance against it once the Trachyphyllia regains it's health (if it ever does).

IMO