I think this will work. First log into your Amazon account. Then go herehttp://www.amazon.com/roku/
(it should have redirected you here, if not then click here)http://www.amazon.com/gp/video/ontv/rok ... v_faq_roku
Then click on the "Edit purchase PIN & Payment settings" button, scroll down to "Your Purchase Pin" You should be able to see your old pin, if not just make one.
PS. The Amazon pin is the 5-Digit
pin you enter to buy or rent movies in the Amazon channel. If you are talking about the 4-digit
pin you enter so you can add channels in the channel store in the Roku. Go here and log into your Roku account.https://owner.roku.com/Account/Login/
Click on the Parental Control
and you should see your pin, and change it if you want, or disable or enable that feature.
Hope this was of some help.