>>305573640
>I don’t know how to finish the job
It's pretty easy. The exports are basically complete. Here's a step by step for everything in blender. Unity isn't any different for any other model. VRC might not need the full body fix any more with the IK update but it's still functional with it. Also the edit to the head/neck bone in the video is for the neck fix so just moving it backwards so it's straight is fine now instead of backwards and down to get rid of the neck bone.

https://streamable.com/rhorw8

There's also another part to one of the steps not included in the video. Once you're reordered your materials so the transparent ones are at the bottom, go into edit mode on the model mesh, select everything, and search for "sort mesh elements" > "by materials" > "by faces" or unity won't know you've made any changes. You might need to do this before and after atlasing but probably just before.