Clash-of-clans – Transfering the Clash of Clans progress from Android to Windows

its very easy....
You just have to reinstall Clash of Clans on your device, and then tap login with G+. When it says, "Do you want to reload your previous village?" Hit cancel.
Done, you have started afresh!

from https://productforums.google.com/forum/#!topic/webmasters/XTmiHxe-VsI

Log into the google+ account, select the "Home" drop down in the upper left hand corner. Select "settings", Scroll down to about half way down and select "Manage apps and activities", Select the edit (pencil) tool for clash of clans and select "disconnect". Make sure you check the box that asks about erasing all activities for this App. It takes about an hour for Google to erase all data for the app, but after that you can then re-connect with the account you want to use.

and another one http://cocland.com/tutorials/removing-clash-of-clans-from-google-account

This was not an easy thing to track down via Google or even clicking through my Google+ account menus. Hopefully this may help others.