First of all, I'm very selective as to whom I disclose my AS to. I only usually disclose my AS when I can see that someone is starting to misunderstand me, and I think that disclosing my AS would dispel the misunderstanding and make our relationship easier. For instance, I have had people notice that I take jokes literally and think that I'm stupid, arrogant, pedantic, or whatever.
Once I have decided to disclose my AS to someone, I first find an opportunity to raise the issue that has caused a problem; then I say that I have behaved as I have because I have AS. I then ask the person what they know about AS, or autism, listen to what they say and build up my explanations from there. It may be a case of saying "Yes, what you are saying is right, that's how it affects me" or "What you are saying is right but it is only one part of the picture, there are others, here are some who affect me" or "You misunderstand the condition, that's what it is really like." Since AS is multi-faceted you can't possibly explain every aspect of it to everyone. I make sure I cover the core aspects, and my key differences and difficulties; and I make sure I don't ramble on on the subject!