Help me "translate" this tutorial

Ok, before everything i must say i’m pretty noob in blender in general, i know only the very basics of everything, I’m more a programmer.
But here it is: I’m creating a game on UE4 and some complex animations like a front flip twist i’m getting from mixamo, but thing is: Mixamo don’t support the UE4 skeleton system and vice versa, resulting in some weird behavior on some animations.
But this guy here in this tutorial :
found a solution, but in maya…
So, my reQuestion(it’s a pun , y’know, request, question… c’mon it’s funny… srly) is someone to help me “translate” this tutorial to blender.
Thanks in advance.