Advice for making a mod.

[rairokun]

Hello, so with being quarantined and all i decided to try my hand at modding. i did some basic tutorials and got a fair understanding from them so i decided to try a few on my own. There lies the issue none of what i have tried has worked. 

 

my goal is to shrink a sim. scale it down to smaller then the knees on a normal sim. i thought it would be simple. make a preset and just scale it down. yet ts4  morphmaker doesn't like that idea.( im still unsure why tbh)

 

Anyone who is more knowledgeable than me have any suggestions on where to start? 

any and all advice as for how to achieve this would be appreciated thanks!