Office 365 Pro Plus force upgrade using deployment tool

I use a Kace script to push out our Office 365 install to our users. It is using Microsoft's Office Deployment tool to do so. The issue is that it installs side by side with the old version of office on the PCs. If my users run the install from portal.office.com it performs an upgrade. I want my office deployment tools script to perform an upgrade not a side by side install. I can't find the code to put in my XML file to force the upgrade of the older version(s). Can anyone shed some light on this? I have spent hours searching and haven't found the answer yet.