Configuring IRM in Office 365 is really easy and works really good. So here is what you have to do: 1) Login into Office 365 as an administrator and got to the Office 365 settings page:
2) You can find the "Rights Management" settings under "Service Settings"
3) Click on "Manage"
4) Click on "activate". Office 365 will now create an Azure AD RMS, which is needed to get IRM running on Office 365.
5) Office 365 displays a short message explaining what you are going to activate now.
6) After a couple of seconds rights management will be activated.
7) Now you just have to select a SharePoint Online library and click on "library settings"
8) You will find the listing for "Information Rights Management" under "Permission and Management"
9) There you can find a lot of options to choose from. As always you first have to click on "Show Options" so see everything.
