Endpoint removal, unable to remove and installing latest clean version

I have a Mac that had Endpoint on it and in the last couple months has had issues with the Mac so they tried to remove Sophos to do a fresh install. 

Unable to remove using Sophos Endpoint uninstalled, it keeps failing.

Unable to reinstall Sophos Endpoint, it says already exist

Tried using Sophos Diagnostic Utility, fails on last section Failure to generate username.tt file, unable to continue and send package to Sophos

Need recommendation please as to what can be done?

Thanks in advance

Added tags
[edited by: Gladys at 3:04 PM (GMT -7) on 5 Aug 2022]