Office Activation Guide (setup.office.com)

Sign in to your Microsoft account here: https://login.live.com
Or create a new Microsoft account here: https://signup.live.com/signup

(Must be a personal Microsoft account, not an organization account).

Go to: https://setup.office.com
Click get started.

Enter your 25-character product key, make sure the account it will be added to is the correct one, click next.

Check the product you will be granted is as expected, choose your language, click redeem.

Important:
There are no refunds after clicking redeem because the key will be used and the license permanently bound to your Microsoft account, this cannot be undone by us or Microsoft.

Before installing your new Office program you should uninstall any old versions on your computer. Old versions often cause conflicts with a newer version being installed, Microsoft 365 will try to override your new install (they want you to subscribe).

Uninstalling your old Office program will not delete your files (Word, Excel, etc.), as they are stored separately from the software. For extra security, consider backing up your files.

Here are links to the Microsoft uninstall guides for Windows and Mac:
Uninstalling Office from a Windows PC
Uninstalling Office from a Mac

Double-click on the Office installer that was downloaded to your computer (most likely in your downloads folder), and follow the on-screen instructions.

Your installation is complete when you see the message “You’re all set! Office is installed now”.

This only applies to Office 2016 Suites or older.

Upon opening an Office App for the first time you will be asked to activate your product with the Office Activation Wizard.

Select “I want to activate the software over the Internet”, and then select Next. Follow the prompts to complete the activation.

If the internet activation fails, try the “I want to activate the software by telephone” and then select next. Follow the prompts to complete the activation.