Make Code a Button/Lightbox

Hello!

I'm currently having a bit of an issue trying to tidy up an embedded code form for my client. I copy and pasted the code for a donation form, and what I'm trying to do is have it appear as a clickable button that opens a lightbox form, instead of having a massively long form that goes far past where I want it to.

Here is the link to view the issue in it's entirety, since a screenshot of the full-length is impossible. 

Essentially I'd like to take that long form to the right of the image, and below the paragraph, and turn that into a "Donate" button, where the client clicks and then that large form pops out into a lightbox. 

Is this possible, or am I way out of my depths here? Thanks in advance!

The site is password protected. What you could do is put the form on a separate page and then use this plugin to have a button that has the lightbox effect linking to that page.

You can follow this guide. (replace contact page with donate form page)