Google+ Sparks – How to Add Sparks in Google+

You might be able to go to the Account Management page then scroll down to "My Products" click edit. There might be something along the lines of "Remove Google+"

EDIT: Perhaps you should have done a google search. I just did it and I found this link. Clearly written instructions on how to delete Google+.

Step 1: Click on Settings icon on the top right of the Google Plus screen when you are logged in and click on Google+ Settings

Step 2: Click on the Account Overview Link in the left pane and the click on the link towards the bottom of this page which says Delete profile and social features – Delete Profile and associated social features

Step 3: On next screen, select the option which says Delete Google+ Content IMPORTANT. Then click the check box at the bottom of the page which says I understand that deleting the service can’t be undone and data I delete can’t be restored.. Then click the button which says Remove Selected Services. This is it.

Go to Manage Account Information and add an additional address.