Go to Microsoft’s activation official website: https://setup.office.com/
Log in to your Microsoft e-mail account (Hotmail, outlook, skype, msn etc.) or register a new account.
Now, enter your product key and wait for it to check your key.
When you have chosen your Country and app Language, press ‘Next’.
See image down below:
Now you can download your Office 2016 program. When the download is completed, install it on your PC/Laptop/Notebook.When the installation is complete, start the program. It will ask you to log in, simply enter your account login.
Done, enjoy your product!