Wondering how people make those edits of booth models

[VrGaming69]

I have been seeing a lot of these the last while and i have been wondering how people adjust the body shape like that. Can anyone help me (and maybe future people wondering) out with this?
Example images:

[Gronar]

Bump

[avatarofcorn]

You change the scale of the bones in the avatar's Armature. Be warned that fitting outfits will get troublesome. If you use MA or VRCFury, there's a chance outfits will be fitted wrongly and you'll have do it the old way by dragging and dropping the outfit bones, then scaling those up. Keep notes on which bones you scaled so you know which to adjust!

[avatarofcorn]

For your reference, you can look at how they did it in here:

https://booth.pm/en/items/4292207

Big and Chibi Presets for: Kikyo, Chiffon, Manuka, Moe, Selestia, Shinra

Good luck!

[VrGaming69]

ohh ok
thanks

[weirdweed]

I wish they would sell presets like that but for the edited ones