I have a 16-year old son w/Asperger's. My best advice is to minimize the talk and explanations. We have to remember that our kids process information slowly. They quickly get frustrated not only because our way of thinking goes against theirs, but because they can't process as quickly as we speak. That can lead to a major meltdown. Like another poster said, it's important to pick your battles. These kids have to learn things that usually comes naturally to us. It's going to be a long process, and it's going to be hit and miss.
Here's an example - We were at a restaurant last night with my parents, my brother and sister. My son has anxiety about seeing people from his old school, where he had a bad experience. He's been in a specialized school for several years, and wants nothing to do with anyone from the old school (even the people who were nice to him - makes no sense, but that's his view). When we got to the restaurant, he remembered that we once saw a girl from his old school there with her dad. He said, "Oh no! Do you think Sarah and her dad will be here?" I said, "I don't see them anywhere. Don't worry." When it was time to order his food, he clammed up. He wanted me to order for him. My mom, brother and sister were encouraging him to order for hmself. They were talking at him from all sides. The waiter was standing there. The pressure was building. My son just looked down and said nothing. I knew he was still anxious about seeing Sarah. It wasn't worth it to me to let his anxiety rise, so I ordered for him. My family, of course, told me I should have made him do it. They don't understand that it's not that simple. You can't just tell him to do something and have him snap to it. His brain doesn't work that way. I don't always order for him. He has learned to do it for himself. However, in that situation, it wasn't worth pushing him. The funny part was that Sarah and her dad did show up when we were eating! She was really nice to my son when they were in school together, and she still asks about him when I see her. Still, he views everyone from that school as bad. I know it's not rational, but it's his thing.