They have jacks that attach to the hold-down points; those jacks will probably be welded to the deck. Elon also mentioned the metal shoes over the legs some tim

They have jacks that attach to the hold-down points; those jacks will probably be welded to the deck. Elon also mentioned the metal shoes over the legs some time ago, and they may also have those, but there's less evidence of those. (You can see the jacks on the deck of the barge in various photos and videos.)