Search "software center" in your lower left search bar.

Click the Icon that appears as "Best match."

2. Find Office 365 in Applications

Scroll down and look for the orange, "Office 365" app. Click on it. 

3. Install

Click on the blue "install" to begin the installation. If this says "installed," Stop! You already have the program.

Just wait until it completes! If the install fails, search for "word" in your search bar. If it shows up, you already have Office installed.