Hi, I have the same question.
It is possible in the original editor
Viewing post in LPC Character Generator comments
Greetings.
That is possible and one of the easing things to mod in the editor.
First I suggest you read Devlog v0.2. It explains how the application loads it's resources.
With that knowledge, you can extract everything from "chargen.pak", and edit the file "data/character/race/human.race" to add the pieces you want. For instance, if you add the line
"tail": [ "none", "cattail" ],
to the "m1" configuration, then regular human males can have a cat tail.
After that there's no need to repack the assets in a new .pak file. Just place the "human.race" file in the folder "<base>/data/data/character/race" and the application will use the human race definition instead of the one inside the .pak file.
Note 1: To discover the id's of the pieces you want you need the open the json files in the "data/character/..." folders.
Note 2: Some pieces aren't configured to work on some bodies (because they don't fit well). If you still want to use them, you will also need to edit those pieces json files.
Have fun.