Extract the rar file and copy the applicable folder into your D:OS EE install folder. Mods distributed as pak files go in My Documents; those as files and folders go in the install folder.
I don't recall what the default install folder is, but it will be something like:
C:\GOG games\Divinity Original Sin Enhanced Edition\Data\Mods\Main\CharacterCreation\HenchManPresets
As for the files in the mods folder being recreated, make sure the mod is disabled in the game, if it shows up at all. Also, try deleting the contents of the mods folder, rather than the folder itself.
Do you have cloud saves enabled in Galaxy? Try exiting out of Galaxy, delete the contents of the mods folder, and then start the game from the executable. If that avoids the files being recreated, it could be Galaxy backing them up, and restoring them the next time the game is started.
