Uninstall

Options

Open you Excel (versions 2007+ supported), go to Office button - Excel 2007 (round button on upper left) or File - Excel 2010/12/16, then Excel Options -> Add Ins. Make sure that Excel Add-ins is selected under Manage (lower left). Click on Go...

Uncheck

On new dialog just locate E4SEO from items provided in list and uncheck it. Finally click OK to confirm.