Learn to use Visual Studio, Visual Studio Online, Application Insights and Team Foundation Server to decrease rework, increase transparency into your application and increase the rate at which you can ship high quality software throughout the application lifecycle
"Well, I removed the TFSSetup account from this group and added the 5 users of the system. This of course FAILED and now (I'm guessing) it removed the TFSSetup account, and couldn't add any of the new users so NO ONE can access the TFS server. How do I fix thix???"
Access is always allowed through the service account, and the service account is always an administrator. You can therefor log in as the service account and re-add the appropriate users to the liscensed user groups.