As a Partner you can manage all of the customers that you have sold Office 365 Licenses to and added yourself as “POR” Partner on Record to.
You access your customers thorough your normal Office 365 Portal. e.g. http://portal.office.com or any other custom domain you may use
To set a user up for partner management, you first need to do this:
1. Click Admin and Office 365
2. Click Users and Active Users
3. Find the user you want to give access
4. Click Edit
5. Click Settings
6. Select the Role you want to give and click Save
Now log out and back in. The partner button should be visible now.