Follow these steps to install and activate your Office 2016 Professional Plus license.
1. Go to setup.office.com
Open your browser and visit setup.office.com. Click Get started to begin.
2. Sign in with your Microsoft account
Log in with your Microsoft account. If you don’t have one, create a new account.
3. Enter your product key
Enter the 25-character key we sent to your email, then click Next.
4. Choose your language and redeem
Select your preferred language and click Redeem.
5. Download the installer
Click Download 64-bit or Download 32-bit, depending on your system.
6. Run the installer
Open the downloaded OfficeSetup.exe file and wait while Office installs.

7. Activate Office 2016 Professional Plus
Open Word or Excel. When the Activation Wizard appears, choose "I want to activate the software over the Internet" and click Next. Once activated, click Close.
Your Office 2016 Professional Plus is now ready to use.