Umm... I thought it was pretty self explanatory... the three methods take a variable from the tile entity and send it to the gui. Since the gui can't read the tile entity since it's on the client and the tile is on the server, the container has to manage their variables to make sure they are the same. That's why you see these methods check if, for example, the last burn time of the gui is the same as the tile entity. If you want to use them, just sub in your variables that you'll be using. If you only want to do exactly what you said in the first post, then just edit the gui. The container should do everything you'd like, but if not, just sub in your variables for the already-existing ones.