How is the transfer of CAL licenses from server to server?

Question

Windows Server

Two packages of CAL licenses were purchased for the server - for 25 and 15 users. Now there is a need to transfer only a part of them (15 licenses) to another server.
Unfortunately, it is not clear from the instructions on the Microsoft website whether it is possible to transfer them one at a time or whether they will be transferred all at once. Who faced this, tell me. I would not want people to lose access to the server due to experiments :)