Is your system automated? Lights and misting etc? Can he come over so you can show him the ins and outs of everything like how to dust feeders and gutload them. How to fill anything with water? I would make a list of what the day/night is. Starting with lights on and the time. And just write it out as if you are going through the day. But if you can get him to come over to show him everything I think that would be really helpful. Otherwise he may be lost since he is not familiar with the care of these guys.
I travel a lot as well. In fact, I am doing the same right now. I'll be gone next week. The best thing you can do is to have the person over at your house and show them what they have to do. Keep a list of tasks simple. Also, feed the chameleon extra of his favorite food and keep the feedings while you're gone simple -- maybe offer crickets. He'll be fine for a few days. Also, make sure you have a spare lamps, bulbs and a manual mister just in case of any failures.
I am fortunate to have a full time employee that is here everyday to take care of our child. She's now becoming an expert on reptile care, too.