Installation

(if you have not already done so)
modify the "Fallout4Custom.ini" file located in "Documents\My Games\Fallout4"; adding these lines to it:

[Archive]
bInvalidateOlderFiles=1
sResourceDataDirsFinal=


Inside the file included here there will be a folder labeled 'KueiNightie';
inside that folder there will be folders meshes, materials and textures.
Copy the files in the meshes, materials and textures folders to the appropriate place in your fallout 4 data folder:
(C:\Program Files\Steam\steamapps\Common\Fallout 4\Data)



If you wish to customise the mesh to match your version of CBBE:
Download and install bodyslide

copy the contents of the folder 'BodySlideNightie' to the appropriate place in your BodySlide app
(C:/BodySlide and Outfit Studio - v3.0a-25-3-0a/fallout4/data/Tools/BodySlide)

Open body slide
click on boy/outfit 'BathrobeNightie'
apply your preset.
click build
replace the mesh file from 'KueiNightie' above with the one created here by BodySlide