Just a simple PowerShell one liner for adding a new license pack for all your users in Office 365. Quite handy while in trial, and you just added for example the CRM Online pack.

First connect to Microsoft Online using PowerShell, and run Get-MsolAccountSku

That should return something like this

PS C:\Users\Anders> Get-MsolAccountSku

AccountSkuId          ActiveUnits     WarningUnits    ConsumedUnits
------------          -----------     ------------    -------------
aeb07:CRMSTANDARD     25              0               0
aeb07:ENTERPRISEPACK  25              0               24

Then simply run this command, and replace AccountSkuId, with the ID from the table above

Get-MsolUser | where {$_.isLicensed -eq $true} | Set-MsolUserLicense -AddLicenses "AccountSkuId"

This command simply gets all users in Office 365, and select only those who are licensed today, and then add the license. You can filter as you like in the where statement.