Basically all you need to do is click on his template and make a copy.
Once you make a copy, the drawing is all yours to do as you wish. A great way is to share the doc with a friend and the game is on. You can go back and forth playing the game of checkers online.
** If you ever have a questions about someone's last move you can always see revision history to see how the doc has been revised!
Embedded below is a short GIF to show you what the site looks like and below that is a 1 minute and 19 second YouTube video tutorial