https://twitter.com/mattBgomez?lang=en - Twitter
Once you make a copy of the document, go ahead and share with another player.
Once the player opens the shared document, they can open the chat box up (if you want to point that out) and chat until they are both ready.
Once decided who goes first the player will simply need to drag the drawing into the proper spot on the Connect 4 board. Then the game continues as it typically would until the player who connects 4 in a row wins.
One item to point out is that if an issue arises, remember version history under File. This will enable the players to see who last went and altered the doc.
Embedded below is a 1 minute and 43 second YouTube tutorial.