Unpack the content of these two files on your desktop (or anywhere where you can easily find them).

Then follow the instructions of this youtube video:
https://www.youtube.com/watch?v=64fVZ9JdwyY

(do not forget to make backups as this process replaces original textures)

In the archiver programm, You will find the original human male body file in seventysix - textures01.ba2 and the bathrobe texture in seventysix - textures04.ba2