So from the Launcher I can find this little wheel up in right corner. Choose Edit Vault Cache Location and I specific the new placement on another hard drive, press apply and I restart.
It made the new folder there but the content is still in the old place.
That was what I ment by moving it manually, thx. Even when the old folder is deleted, it creates an empty folder in the old place, though it seems to work so having the files on the other drive - so far.