I have tried to disconnect the evap purge valve on my 2001 330i, but got stuck with the bottom hose, can't remove it. Bentley manual states "(2) release the bottom vent hose by pressing the locking bar and detaching". There is a plastic clip that seems to be holding the bottom hose connector in place, do I have to remove it? Do I simply pull the hose off the valve? I don't really want to break off anything...