By virtue of the terms and structure of FS's typical management contracts, it is essentially impossible to remove them unwillingly.
Of their relatively few de-flagged properties, most deflaggings are because FS wants to pull out.
One way for owners to nudge FS to the door is refuse to spend on capex (likely breaching the owner's obligations under the management agreement). I've not heard that to be an issue at the Dublin property, but I wonder. FS doesn't just pack up and leave upon simple request.