Cannot Remove SEP from Windows 10 Machine

My machine was running Win 7 with SEP, then it was upgraded to Win 10.

I cannot install the latest Win 10 updates because SEP must be uninstalled, first.

I cannot uninstall SEP from Windows Control Panel.  The uninstall terminates without error, but SEP is not removed.  If I try to disable SEP, I get "this app can't run on this pc".  I cannot disable the SEP Service, not even from my Admin account, because I do not have "System" permissions.

I tried downloading and running NIS 22.5.5.15.  I get "Another version of a Norton or Symantec product has been detected on this computer..."  It refers me to your tech support page which tells me to remove SEP using control panel.

My SEP is version 12.1.2015.2015.  It was obtained under the DoD Home user License and was installed on 11/29/2013.

All I want to do is remove SEP!!  Can someone help me, please?