Unwanted Guests

You know how sometimes someone will come over, uninvited, and then you can't get them to leave? We have had such guests for a few days now. Some incontinent birds have taken residence in our BBQ grill and have not only converted it into a bedroom, but a bathroom as well. I think we have finally gotten rid of them, but they certainly made quite a mess during their stay. Anyone want to come over for BBQ bird with a side of guano??