So if by any chance you want to delete and redownload all mods you are currently subscribed to, then there is an easy approach to do it, I am assuming that you use Kaedrin's Mod Manager to manage your mods, if you don't then shame on you, you definitely want to switch from vanilla to KMM.

So, steps are very easy:
1.
close game, warhammer launcher, everything related to game, only open KMM, under Tools select CLEAN DATA (this will delete all files related to mods from your WH II installation Data folder), vanilla game files and folders will be kept no worries.
CLOSE KMM
WARNING: you might have some .Movie mods that you installed manually, copy those somewhere safe before you do STEP 1
1.1 OPTIONAL residual mods
you might have some mods still in the Data folder (probably manually installed mods you dont want anymore) so just delete them
2.
Go to Steam/Steamapps/Workshop/content/594570/
and DELETE everything from here
3. Start Total War Launcher and switch to mods tab, all mods you are subscribed to should automatically start downloading and you should also be able to monitor the download progress from the launcher or Steam itself

I hope this'll help some of you. :)