Thank you for your post.
You may try to remotely uninstall TeamViewer (start from Step 2) if you have administrative right on the remote device. Please noted that once you successfully initial the process on uninstalling TeamViewer on the remote device, your remote session will be cut off and you will have to find an alternative way to check for the unistallation result and to start remote connection.
Hope it helps. Feel free to contact us if there is anything we may assist further with.
I was hoping to do this remotely since access to the computer is difficult and no one there would be able to help. I did assume that I could do this remotely, despite losing the connection in the process. But that raises this question: can I leave out the registery updates without affecting the basic uninstall? If not, I'll have to find a way to get there.