[javascript] Add custom buttons on Slick Carousel

Why you cant use default CSS classes and add some your style?

.slick-next {
  /*my style*/
  background: url(my-image.png);
}

and

.slick-prev {
  /*my style*/
  background: url(my-image.png);
}

Are you used simple background css property?

in example: http://jsfiddle.net/BNvke/1/

You can use Font Awesome too. Don't forget about CSS pseudo elements.

And don't forget jQuery, you can replace elements, add classes, etc.