Monitor Plus is a premium feature from Mozilla Monitor, that warns you when your online accounts have been compromised when a data breach occurs, and automatically removes the exposures of your personal information on the data broker sites that are selling it. We help you fix exposures of your information from two different sources: data brokers and data breaches.

To go back from Monitor Plus to Mozilla Monitor’s free version follow these steps.

Open your web browser and go to the Mozilla Monitor website at monitor.firefox.com.
Sign in to your Mozilla account.
Select your profile icon in the top right corner.
Go to your Settings.
Go to the section Cancel premium subscription and click Cancel from your Mozilla account.
You will receive the following message.
To continue, write the reason for your cancellation and click the button Continue to cancellation.
You will be redirected to your subscriptions, go to Monitor Plus and click Cancel.
Mark the checkbox to agree to the cancellation terms.
Click the Cancel Subscription button and you’re done!