Butterfly pull-ups

I have heard a couple people say they want to learn and do butterfly pull-ups, but aren't too sure where to get started...

Here are some tips and tricks you can do before or after class:

WOD for 7/3/2017

6 ROUNDS

400M RUN

12 KB SWINGS 1.5/1

21 PULL UPS

9AM AND 10AM ONLY FOR 4TH OF JULY