help, getting rid of coral eating crab

[EMBRYOGUY]

The situation is i have a hitchiker crab,(very small) buried in a small hole in the center of my lord colony. the polyps around the hole are dying off but all other polyps are full and thriving.

my question is, how do i get rid of this crab?

freshwater dip? if so how long?

thank you in advance.

 

[Gobie]

Screwdriver in the hole, twirl around a bit.

 

[EMBRYOGUY]

gobie! we think alike!

i tried that but aparently the hole has branches and after doing it. the crab still appeared and eating away that night.

maybe i can get a larger screwdriver.