Remove Nivo slider

Hey, hope someone can help…. I obvously know how to turn off the Nivo slider in the theme settings, however, what I’m really trying to do is remove the plugin files completely!

I want to make a really lightweight website (for speed purposes) and would like to get rid of some of the script calls in the header….

Anyone know how I can remove Nivo Slider and possible the Flexslider too?

Hope that makes sense!

Thanks in advance…