How to kick/remove a user from a room using the Admin API

[jappyjan]

Since Synapse currently does not support (as far as I know) access control to rooms based of SSO roles/properties, I would like to write a script/application that runs alongside my Synapse installation and automatically adds and removes users from rooms based on their SSO properties.

I did look through the Admin API documentation and was able to find the room join endpoint, but it seems there is no endpoint for removing users.

How can I remove a user from a private room using the Admin API?

[MadLittleMods]

This kind of question is best asked in #synapse:matrix.org. If you do end up asking a question there, please cross-link it here so others can find the answer.