Topic: How to Downgrade or Uninstall ViEmu for Visual Studio 2015

I have ViEmu version 3.8.0 installed with VS2015.

Yesterday, ViEmu stopped working and now tells me that my license is still valid but I need to use an older version of ViEmu.

Fine.  So I downloaded "ViEmuVS2013-2015-3.6.0.vsix", but when I try to install it, a pop-up appears and says:

"This extension is already installed to all applicable products."

ViEmu 3.8.0 refuses to work unless I downgrade to an earlier version of ViEmu.  But ViEmu 3.8.0 also refuses to be downgraded to 3.6.0.

How do Uninstall or downgrade ViEmu?