[Plugin: SimpleModal Contact Form (SMCF)] Easiest way to edit content of the form

I just want to be able to add my own content in the modal, specifically a script from Aweber for a newsletter signup. I’ve farted around a bit and can’t get my head around hacking it, so I gave up and left it alone. I even thought of skipping the plugin and using the basic modal scripts from the authors site and copying the style of the contact form modal I’m also using, but that seems like a pain in the arse. Is there a simple way to add the code you want instead of the form code?

http://wordpress.org/extend/plugins/simplemodal-contact-form-smcf/