In the top menu bar, select the Apple icon System Preferences Sharing (third row.) In the Computer Name text box, update your Mac's name and then close the window. Restart your Mac and then activate Office. 'You need to activate Office for Mac within X days' after activating already.
Microsoft has put out the free download of Office 2016 for Mac public preview, without any Office 365 subscription required. The new software includes support for Retina displays, iCloud syncing, and looks like the versions of Office currently available on Windows and mobile.
You can begin the free download here.
Once you download the 2.6GB file to your downloads folder, click on the Office Preview Package to get started. You will be guided through the necessary steps to install this software.
Tip: I had to upgrade my OS X because you can't install Office for Mac with any version of OS X below 10.10. To see my tutorial on how to upgrade your OS X go here.
I also had some internet interruptions on my initial download to my downloads folder and had a hard time opening the package because it did not download the full 2.6GB. Make sure that you fully downloaded the package.
The software license agreement comes in many languages, this one in English. Once you read the agreement, you will have scrolled to the bottom. Click continue to agree.
You will then be prompted to agree. Once you do you will select what users of your computer will have access to the software to select the destination for install. You will need 5.62GB of free space to install. Select and click continue.
I want all users of my computer to be able to access Office and made sure to have the available space. Now I am ready to install. I click install. I had to wait a few moments for the installation to complete. Then I was notified that the installation was successful. And my installation is complete.