The Office 365 Admin center allows an administrator to manage active user licenses for a single user or for a group of users as a “bulk” action. Microsoft provides detailed examples of how to accomplish this if you know which licenses are required and available.
This image shows that an organization is out of available Project Online Premium licenses. Notice that unlike the other licenses, it does not display an available license count for Project Online Premium here.
Let’s assume in this instance that instead of buying an additional license, you just want to reassign one. What if you don’t know what licenses are assigned to specific people and you want to see the assignments without having to export and parse through an Excel spreadsheet? You can simply browse to Billing > Subscriptions then select the associated license subscription. Here it tells you how many licenses were purchased for this subscription versus how many are used.
Next you can click on the “Assigned” link, which will pull up a new page displaying all active users that have this license assigned.
There is also a way to create custom views based on license assignments from this page, but it is simply another way to accomplish the same goal. At this point, you can select the user(s) that you’d like to make license changes to according to the steps that Microsoft outlines here.