This option is available in the “Manage Watchlist Groups” module in “Manage Search Preferences”. In order to edit or delete a custom watchlist group, you will need to select the group from the Watchlists Group dropdown and then choose Edit or Delete. Edit allows users to add/remove watchlists by selecting or deselecting them from the list below whereas the Delete option will permanently delete the group. Please note that you cannot edit or delete the pre-defined watchlist groups. You can edit or delete a user defined/custom watchlist group.