So... You have created an additional FTP user. You will have an FTP user name and a password.
The username will be in the same format as an email address
Type the following into your browser and hit enter.
You will be presented with this screen:
Enter your details and the CAPTCHA code, and click Log-in Now, where you will see this screen:
Click your preffered option for unlocking, and you will see the confirmation screen:
Click the Log out button and that's it!
If you unlocked by IP, then be aware your IP address could be dynamic and get reassigned to a different one, at any point, without you knowing. Just re-access the FTP unlock control panel, and re-unlock it.