AnimeMusicVideos.org

Well I'm just starting after effects but I've been doing sony vegas and photoshop for a while so do we just mask characters out of the scene and put different characters in .....?

umm..i'm not exactly sure what that is...sorry

Ok, so basically lately I've been watching a heap of AMV videos by BestAmvsOfAllTime and theres just a couple that have inspired me to try something
so heres the question, does anyone know how to photoshop or whatever program you use another completely different character into your video..?