Pliers
But if it's a plastic 'cork', it makes no difference to just shove it through.
( Methylene Blue - electrohead, Thu 4 Jun 2009, 22:51, archived)

Yeah, the plastic ones are handy that way.

( Esme Weatherwax I swear on my tash it's daycent hash, Thu 4 Jun 2009, 22:55, archived)