I just stumble upon this guide to remove DRM from iTunes AAC M4V M4P on Win and Mac legally, you can take it as reference
OK, first let me just say that I'm not trying to pirate anything! But I've learned how I can stream content from my iMac to my Nintendo Wii to watch on my TV. Basically, using my Wii as a stripped-down Apple TV. But from what I've read, movies purchased from iTunes have DRM and I can't watch those over the Wii. Is there a way to remove DRM from movies that I've purchased from iTunes?