How do I Change buttons in the plugin to use bootstrap styling?

Hi All,

I'm building a membership site with the plugin and a theme built around bootstrap. I'd like to keep all the formatting consitent and want to change the classes on the buttons in the form to match the rest of the site.

I've been looking through the files for the plugin and I'm just lost in the mix of JS, php and html.

Ideally I'd like to just change the button classes individually but if there's a better way to go I'm happy to give it a try.

thanks
Sim