Moving a guest after they have checked in?

[Ariel32]

My co-host accidentally checked a guest into the wrong unit.  They have been here for several days already, and I need to move them to the correct unit for our records.  How can I move them?  I have temporarily blocked the dates of the correct unit so that nobody else reserves it.  I unblocked the dates, then tried to move the guests, and it is telling me the dates are unavailable.  HELP!!