When the time comes to swap shells, the hermit crab doesn’t leave its Calliactis polypus anemones behind. The crab tugs on the anemones one-by-one, gently peels them off the old shell and places them on the new shell. They will only detach from a shell when coaxed by a hermit crab – Atlas of Living Australia.
Here’s a Youtube video of it in action
https://www.youtube.com/watch?v=dYFALyP2e7U