I'm a little unconventional here, but with that kind of thing I usually try talking to it and frequently enlist the aid of a friendly angel or five as sort of cosmic bouncers to escort the thing off-premises if it gets confrontational. These things generally have some reason why they're acting hostile, and if you help them see where they've gotten off-track, they leave happy. Then again, if that isn't a familiar tactic for you, it's not one I recommend trying on something hostile first time out - you can end up sustaining some serious spiritual damage (or physical if you're really sensitive to that kind of thing).

If you want something quick and easy, visualize a rose above or on the person affected. Roses are a strong protector.