Manage Office 365 on Installed Devices
Office 365 can be installed on up to 5 unique PC or Mac devices. The tablet or mobile installations do not use up one of your 5 computer installations. You can deactivate a computer installation to use somewhere else.
Install Office 365 Tablet / Mobile
A helping hand to get you up and running with Office 365.
Office IT Pro Blog Post
Read the "Manage Devices" blog post for instructions.
HOW TO MANAGE DEVICES