The secondary password system has been in place since Chapter 2 came out in 3Q 2009. And even old-timers like myself--don't let my join date fool you, I've been playing since early 2009--have secondary passwords on their original, old accounts. In addition, if you create a new character on a different server, you are prompted to create a secondary password for that server.
Having said all of that...
To reset the secondary password for your account, you will have to go to our Support Portal and create an account. When you create the account, you will need to use the email account that is linked to your game account. You must do this, or Support cannot help you.
Once you've created a Support account and have logged in, find the "Ask a Question" button. Click it, and you will see a web fiield which will allow you to enter a subject (reset secondary password, in this case), enter your request in the text box provided, and then select the Product (RoM) and Category (My Account), along with your account name and main character name.
After that, you can indicate the US servers and the server your account/character is on.
Be aware that you will receive an automated response. Please answer this, as it indicates to Support that the issue is still active. It may take several days for Support to reset your secondary password. Once you have received their second response, you should be able to initially log in on your game account and then create a new secondary password. Please write it down and keep it in a safe place.