Office.com/setup | Office.Setup | Install Office.com
INSTALL OFFICE SETUP
If you are reinstalling Office, you have already redeemed a product key, or you are installing Office at work or school and know you have a license, then go to the section sign in and install Office on your PC or Mac.
However, if this is the first time you're installing Office, you may have some pre-installation steps to do first. Expand the Learn more section below for more info.
To change from a 32-bit version to a 64-bit version or vice versa, you need to uninstall Office first (including any stand-alone Office apps you have such as Project of Visio). Once the uninstall is complete, sign in again to www.office.com and select Other install options, choose the language and version you want (64 or 32-bit), and then select Install. (See Install Visio or Install Project if you need to reinstall those stand-alone apps.)