At ballymackey we are undergoing that at the moment. Basically the former Toomevara players (who were a Premier Division side) are now playing for us. It takes time but basically by the time the u-16s and u-18s come through no one will know the difference.
Similar thing happened with Arra Rovers when Newtown Celtic folded. Its funny when they joined they were basically two Premier Division clubs but now they are struggling in the 1st!