1. Ask all your users to uninstall the Chrome Extension "Groove".
2. If you added a site for email open tracking (not common), you will want to deactivate it.
- In Salesforce from Setup, Click Develop | Sites.
- In the row Groove click Edit.
- In the field labeled Active Site Home Page, delete "GrooveTracker" so that the field is blank.
- Deactivate the site by unchecking the field Active. Click Save
3. Un-assign all users from the permission set "Groove Standard Permissions":
- From setup click Manage Users | Permission Sets
- In the list of all permission sets click on Groove Standard Permissions
- At the top click the button "Manage Assignments" - this takes you to a list of all users that are assigned to the Groove permission set
- Select all users by clicking the check box in the top left corner
- Click the button Remove Assignments - all users are now unassigned from the Groove permission set
4. Uninstall the managed package "Groove".