In Firefox, hit F12.
Go to the "Inspector" tab
Click the icon next to it called "pick and element from the page"
Hover your mouse slightly below the video box until you find where the inspector tab will show text and a vimeo link
Copy that link and open it in another tab to make sure you've got the right link
Go to
and paste the link
Click "start"
When your options for download show up, I recommend choosing merge. It will automatically choose the highest video and audio to merge and download