This is a 38 card sub-deck. It is added to the 68 card Main Tribal Deck. Remove the 6 creatures there.
You might be wondering why I remove Changelings in the Main Tribal Deck, then re-add them here. That's because I actually have more than one "Main Tribal Deck" built, that have different cards in them. Main Tribal II Deck, for example, doesn't have changelings in it, it has 6 other creatures like Sakashima. I'll upload Main Tribal II sometime soon.