Hard to say without more info. How much do you know about web design?
The control panel is probably for doing back end type things. Look for something in the control related to
FTP and make note of all the details.
Go to
http://filezilla-project.org/ and download and install the filezilla client. The with this new program add a new site and enter your
FTP details. That should show you the 'insides' of your website. You can download these files, change them, then re-upload them with your new changes.