Here is a video which have been requested alot, how to download files via MashUp Add-On Direct download or Using JDownloader, i have covered both,
Things to Know:
1. Jailbreak your AppleTV 2
Seas0npass http://youtu.be/bXvOJAH9KAo
2. Tell Difference Which AppleTV your Holding ( AppleTV 2 or The New AppleTV 3)
http://youtu.be/Ns1jMAhVa8Y
( If still confused, search google to know which one you have )
3. Install MashUp Add-On On XBMC Via Fusion Servers
http://youtu.be/oWjSsLN0V3Y
4. If Your having issue Updating MashUp Add-On
http://youtu.be/nNJAjQ7hrJU