NOTE: Information good as of 7/21/2015 and is subject to change!
With the upcoming Power BI General Availability, you may be in a situation, with your Tenants, to assign a license to a bunch of licenses to your users. This may be for the Free or Pro license. I wanted to show how you can do that within the Office 365 Admin Portal.
Within the O365 Admin Portal, we want to go to the Active Users screen which is under Users.
From there we can select the users that we want to assign the licenses to.
After your users are selected, click Edit on the right.
This will bring us to the Bulk edit users screen. We can just click next on the Details and Settings screen, unless you actually need to adjust something there. What we care about is the Licenses landing page. On the Licenses landing page, I want to select Add to existing license assignments. Then select the license you want to assign, followed by Submit.
This should then show you that the change was successful.