Download the distribution zip but don't unzip it. 


Right click in the left pane and select Import.
From the wizard, select General and then Existing Projects into Workspace.
Click Next>>

In the next pane, browse/navigate to the zip file you downloaded and select it. 
Click Finish.

You are completely installed. 

Do a Run as JUnit with any test file as a JUnit Test. You should get a green bar.