You can easily remove yourself from any Community group that you've joined. The group is still available from the main list of groups, but it is removed from your My Groups section.
To unjoin a group, select Community from the main (left) navigation menu, and select the Groups tab. Your joined groups appear in the My Groups section.
In the My Groups section, select the group you want to unjoin, and select the Unjoin button.
You are removed from the group, and the button's label changes to Join. Select the Back button, and notice that the group is no longer listed in your My Groups section.
You can rejoin the group at any time.