Question : How can I clear Terminal Server Device CAL token?

I have a terminal server with 20 CALS per Device. According to the terminal server license manager they are all in use. Can I manage TS CAL per device  tokens?
How can I deleted an token?
How can I set the lease time of an token?

Answer : How can I clear Terminal Server Device CAL token?

You can't. TS CALs are tied to a specific device, they are *not* concurrent (so if one device logs off, another device can *not* pickup the same CAL).
A TS CAL can only be used on another client if this clients is replacing an old one. In this case, there's nothing to do for you: TS CALs will be refreshed during client connection on a regular basis and are leased to that client for 52 to 89 days. If the CAL isn't renewed, it's available again after these 89 days at the latest, which means that a new client can work with a temporary license (which is valid for 90 days) until the old one is released.
There is no manual intervention possible in this process.