1. Go to Your Profile, Managed Licenses

 

2. Go to Named User Tab

            

 

3. Add the User to the Named User Licenses

Click on the ID and then click on Add on the window that opens.

 

               A pop-up window opens as below:

 

Select the user from the drop down that needs to be added to the Licenses and click on Submit.

The users added here should now be able to use the licenses.

To have a better control over the licensing, creating Groups would be useful where only the required users are added and the right license and be assigned..

Please refer to the Knowledge Base for the same:

KB0117073 : Creating Groups and Assigning Licenses - Managed Licenses