How to download all your purchased Instrumental tracks, and other keys?

Just follow the next steps:

1- Log in (sign in) to the website.

2- On the Bottom in the middle column you will see, "Service: My Account"
(Just click there)

3- There you have access to all your purchased files.
Click on  i (the small letter next to the price of the Instrumental Track you bought).

You will arrive at the Download page.