Go into settings/apps/manage/all/GMail, then click uninstall updates if it's there. If the Uninstall button is greyed out (disabled), then you have it in the system/app folder. Just go into recovery and flash the zip from the OP.
Go into settings/apps/manage/all/GMail, then click uninstall updates if it's there. If the Uninstall button is greyed out (disabled), then you have it in the system/app folder. Just go into recovery and flash the zip from the OP.