You can do this one right after completing episode 3. Once you've finished the episode you can play Chattermax the minigame found in the bottom left corner of your screen.
Start the game and the aim is to hold on to Chattermax as long as you can until you get a star. Look in the top right corner and you will see the bar fill up and once it's full you'll gain a star and release Chattermax. Each time you gain a star you will have to chase Chattermax again and build up to another star until you reach 3 stars. 3 stars wins the game but if not then the person with the most stars wins.
I found it easiest to run to the tables each side and wait behind them until someone gets close, then run in the opposite direction and by that point you should have gained a star. There is a time limit but I had no issues gaining 3 stars every time.
If you need more help/guidance with this you can follow my video below which will start from this point: