READ THE README. Extra install details are inside.
Install using Jennie’s Custom Anims mod. Get it here: How to add Custom Animations easily
Make sure you follow their guidelines on how to install that mod properly and how to install animations using it.
Disclaimer: It floats a little, use object spooner to lower the ped so the feet are on the ground if you’re bugged by it.
With the angles it’s meant to be used with, it won’t be noticable, so it’s not necessary.
Credits:
struggleville