Hi lakegirl... Just got the answer to our question. Looks like no banks on the island will convert the extra currency I've got, however you can get your Pesos exchanged at Milo's Centre on Middle Street. It looks like an office to pay electric bills or something, but there's a bunch of flags outside and a sign that says Western Union, etc... Go in there, get in the Western Union line, and they'll do it for you.