"Import the FBX into Blender and then use File>External Data>Unpack All Into Files and choose from the dropdown how and where you want to save them

or

Do it manually by importing the file, then go to UV Editing workspace, click on the image icon at the top and select a texture, then go to Image>Save As and save to disk"

Finally got around to trying this out, much thanks. Seems that the SPS sockets are buried all throughout the armature