@damian
In this link there a gallery running:
http://support.advancedcustomfields.com/forums/topic/carousel-slider-implementation/
1. Copy the code.
2. Download the .js file and the .css file (http://flexslider.woothemes.com/) and copy in your theme.
I delete the code about THUMBS.. and check my example:
http://wac1.ceroonce.com/recetas/risotto-de-remolacha
😉