Here are the steps you can follow to change your subscription plan in Google play for JOIN.
- Go to the Google Play Store app on your phone.
- Click on the Menu Options button (three horizontal lines).
- Select Account and then select Subscriptions.
- From there you will be able to cancel your monthly/Quarter/Yearly subscription, and purchase a subscription of your choice when your current subscription expires.
You will receive an email confirmation from Google Play that indicates you have changed your subscription plan.