I doubt anyone's bylaws allow that sort of switch to take place as a matter of course. It would wreck havoc as far as parlimentary procedure. But check your bylaws and see what they say about conflict of interest. If there is nothing I'd suggest you follow whatever the course you have laid out for position resignations. Allow those 2 individuals to resign (in writing) and then either hold another vote to elect them into their desired positions or if your bylaws allow--they may be able to just step into them given the vacancies and no other viable candidate and serve for a period of time before they are "confirmed" through a general membership vote. If you don't have that sort of clause you may want to consider adding one..