Plan A avoid/ignore.
Plan B confront.
If I feel like actually trying, I'll purposely misinterpret what they say to be nicer than what they mean, and carry on the conversation that way. Some people stumble and just start acting neutrally or even decently then.
Usually I'll just ignore them though. Don't really care most of the time. I'm willing to burn bridges for peace of mind.
One day dude, I'm just gonna get off the bus, and I'm gonna run in the woods and never come back, and when I come back I'm gonna be the knife master!
-The Rev