How do I integrate Page Builder into my existing site?

(and does every page need to be constructed widget-by-widget individually?)

I’ve had a hard time finding the answer, so I figured I’d ask. My site, http://www.reeftechs.com has been built with the LGC Columns plugin where I needed columns. Yours is much better. So how can I rebuid this site with your plugin without disrupting the existing site?

Sorry for the question, but before I pull any triggers, I do need to be sure. Thanks!