How can we get rid of raccoons?

Our house has a low-pitched roof. It's almost flat, and there's not room for an attic, but there is a space of some inches --maybe 8 to 10 or 12 inches in places -- between the roof and the ceiling. A family of raccoons has gotten in there and they are having a big time and sometimes having squabbles and parties. How can we get them out of there?

Someone told us they had heard of blasting them out with loud music ... but our next-door neighbors might not like that.

There is a small visible hole in the outside wall, up under the eaves, that the raccoons use as an entry. I don't think it would do to close that up, because then they would be trapped inside the house, and of course we wouldn't want one to die there.

Does anyone have any suggestions on how to get rid of those raccoons, without getting into major re-roofing?