I just found out that Terminal services manager does not exist in Windows 7. But fear not, the Remote Desktop Services Manager will do the trick. It is included in the Remote Server Administration Tools for Windows 7, which can be downloaded from here.
I was also able to figure out how to actually enable the feature, in “Programs and Features”, “Turn Windows Features on or off”:
Go to “Remote Server Administation Tools”, “Role Administration Tools”, and enable “Remote Desktop Services Tools”.
There! Now you’ll find the Remote Desktop Services Manager in your start menu — and can start kicking out stale remote desktop connections from your servers. 🙂