Don't be afraid to ask for help. I'm making changes to this tutorial all the time. Your feedback is greatly appreciated!
Step 1: Install UE 4.22 with Epic Games Launcher
Step 2: Extract Assets
Step 3: Import to 3D modelling application
Step 3a: Import the base mesh to Blender
Step 3b: Rename everything
Step 3c: Apply the morph targets
This is a good time to save your .blend file!
I've made a bit of progress on this, not sure if this is useful to anyone because I'm still not there yet, but I'll throw it out anyway.
The potential to edit scale by just messing with the main file is possible by applying transformations to the rest pose. While in blender, click on "pose" then grab either the root (or hips, doesn't matter), scale to your heart's content, then ctrl+A and apply to rest pose. You'll have to do the same exact thing to your mesh afterwards, so push S 1.