How to cure minecraft witchery vampirism with player files?

I run a server with witchery mod installed, one of my staff cheated someone into a vampire but they don't want to change back is there a way to change them to human in any of the files? And if so, how do i do that? I can't find anything about it anywhere.

You can edit their player data file to modify what Witchery stats they have. You'll need to download NBTExplorer to modify the files -

Open NBTExplorer and go to "Open" then navigate to your world folder and find the player data folder. Then use NBTExplorer to open up their data file, scroll down to "WitcheryExtendedPlayer" and change the values

No idea