2.Microsoft Office Professional Plus is the Microsoft Office version that is part of particular Office 365 subscriptions, for example Business Premium.
You must have an active Office 365 Subscription to use Office Pro Plus.
It can be installed on up to 5 Devices, including Windows (Laptop/Desktop/Hybrid), Macs and other Devices.
1. Login to Microsoft Office 365 Online Portal (Microsoft Online Services) http://gjscomp.com/1yKcRGt & Sign in With Your Organisational Account (email address & Password).
2. Once you are logged in, click the cog 
on the top right hand corner (settings) and go to 'Office 365 settings'.
3. On the left hand side of the page there are a list of options. Click on section 'Software'.
4. After you click Install, a pop up will appear at the bottom of your Web Browser, click 'Run'. The installation process will then proceed automatically.