You can download and install Microsoft Office 365 directly from https://outlook.office.com

Once you’re logged into Office using your Dartmouth credentials, click on the grid in the upper-left corner of the page:

On the drop-down, click “More apps”

 

Next look to the upper-right and click “Install apps” and select “Microsoft 365 apps”

 

Another window appears where you choose “Install Office”

The install will download (it’s a big file so may take a while). From there follow the prompts to complete the installation.