Haddoni are usually attached to the bottom glass or whatever you have under your sand. If it is, then you would have to dig up the sand, find it's foot, and use a razor to scrape it cleanly. Wear gloves or put your Han inside a plastic bag. You don't want to touch a carpet with your varehand especially I it's a healthy one.
Gigantea are the one that attach to the rock. I would do what Taylor suggested.