Hi, you should be able to change your password quite easily.
If you're logged in to the forums, go to the forums main page.
At the very bottom you should have a link to "View Your Profile", followed by your user name and status as a new heading.
Beneath that you'll find quick links to help you change your settings, the last of which is a link titled Password.
Once you click on that, you'll have to type your original MC password, the new one you wish to have, and then confirm it by typing it a second time, then click on the Save Changes link/button when finished.
If this doesn't work...
Please do not delete and create a new secondary account.
1 You won't be able to delete your MC account, only a member of the staff can do that, and for a long-time member such as yourself the administrator might be the only one able to do so.
2 Creating a secondary or duplicate account is against forum rules, as it triggers our Multiple Accounts tool.
3 Contact Phillip through the forums' "Contact Us" link to see if he can help you achieve the desired password change.
Hope this helps.