Android reverse apk signed with google key

On google play me and my android team accidentally enabled signing apk with google key. Now we want to revert it and allow all the users that already installed apk that is signed with google key to uninstall apk and install new apk that is signed with our key.

There is option to update key but this new key will be used only for new users and new installs. Old installs will still use the google key.

Is there any workaround for this?