1. Click the Apple menu in the upper-left corner of your screen, then select App Store.
2. Search the App Store for 'Microsoft Remote Desktop'. You'll get a few results, but this is the app you want. It's free, so go ahead and install it:
3. After the App is installed, you can launch Remote Desktop by either pressing Command+Space (to launch Spotlight) and then typing Microsoft Remote Desktop, or you can select it from you Applications Folder:
4. You'll need to create a new connection. Click the button labeled New, then complete the information below. You can can name the connection anything you like ("TSS Network", "TSS RemoteAccess"), but you'll need to enter the connection (remoteaccess.tetonscience.org) and your TSS username and password. Once you've finished this step, click the small red button in the upper left corner of the dialog box.
5. To start a remote desktop connection, select the connection you just created and click "Start":
6. You'll get an error message about a root certificate; this is normal and OK, you can click 'Continue'. After a few seconds, you'll see a Windows Desktop appear on your screen and you're in! This new window will act like a Windows 7 PC and allow you access to TSS shared files. When you're finished, don't forget to click the Start Menu and select "Log Out."
Here's a video on how to set this up: