Convert CC user-licenses to shared-device licenses

Form your query it seems that you have Named user licences. You'd like to return these and get Shared Device licenses instead.

I'm not aware of an automated way to convert Named User licenses to Shared Device licenses. My guess is it would depend on your existing plan and contract and most probably many other criteria. For example, pricing is most likely different, so a simple swap might not be possible.

I'd suggest that you contact Adobe Support. They can review your account and then try to guide you with possible solutions.

See if the following article helps

https://helpx.adobe.com/enterprise/kb/migrate-dl-to-sdl.html

In case you need more help you can contact support. To contact support. login to your account and navigate to the URL below. Make sure that the browser has cookies enabled, and all script blockers are disabled.
https://helpx.adobe.com/contact.html?rghtup=autoOpen
Type AGENT to avoid bots and talk to a human.
Also, be mindful of answering anyone who sends you a private message. See the following for more information about scammers
https://tinyurl.com/y7cfrr7y
-Manan