I have found that if you place the pin in the wrong direction, i.e. the half round facing the wrong way. This allows the pin to be pushed in most of the way. Just as the head of the pin hits the top of the receptacle, keeping pressure on it, turn it to the correct position and finish pushing it in. This method has worked every time for me. In my experience, the two prongs want to separate if you try pushing the pin in in the correct orientation. A small pair of needle nosed pliers speeds things along.