Scripting installation

Hi, for years we have been using the Enduser Protection. Since a week we've changed to Intercept X via Sophos Central. I checked the page they are suggesting about installations:

I'm trying to set up a GPO like in this page, but it seems that it doesn't install because the old one is still present. Can I add the uninstallation part in the script, and won't this pose any problem as I thought you need to restart before you can install the new one. Or am I  missing something?