To view previously purchased videos, click on any of the paid Videos (not the first free one), and then click on "Buy from $3" to get to the screen where you can sign in. Sign in with your email and password, you can also reset your password if you don't know it. Watch video above to see how this is done.
Once you are successfully signed in, you can then view the Tutorial you already purchased.
Note: there is also a Rental option for $3 that only is good for 48 hours,
so only the $5 Purchased Tutorials will be viewable again.