Hi,
Once your gedcom file shows up in Ancestris, go to the View menu, Table of Places, and from there you can pretty much re-arrange all your locations super easily.
First define how your ocation should be defined (Modifiy Place Format button), and then use the "speadsheet" like in excel (edits, copy/paste, drag-n-drop).
Let us know if that helps.
Regards,
Frederic