Funny i just downloaded it with no problem and im not a premium user if you cant even get the file how the heck are ya going to jtag the unit as this is going to be 10 times harder for ya.
As mentioned above you don't need to be a premium user, but that site does limit the free user download availability during peak times. If you read carefully what's on screen when you click the 'free user' button it will tell you this. Just wait a while until it's quieter
Try this. The image shows the pinouts for TheBox (Starview 2) but I think it should be the same for TheBoxSuper (Starview 3). TheBox JTAG pinout