Even though you have solved it already, in the event anyone actually searches for this, you don't always need a special tool either. The female portion of the connector under the ears often gets grime underneath it - I actually found a use for WD-40 and use the small tube to wash out the underside of those tabs. Once the underside is clean, press the tabs together (finger or pliers) and pull the line out. The tabs stay with the female portion of the line and come in a quick-install kit from the dealer.