Sign in to your account, go to 'My Library'. There you'll see the files ordered.
If your order is marked 'pending' it's not ready for download, if it's marked 'completed', just look at the right side of the filename.
Look for the little 'square' as you can see in Larrys screenshot, and click it.
Warning: Site is still slow as h***, and downloads often get broken before finish.
Then just try again.... and again...and again.
Yamaha say it will be better within a week or two. 👍