I have found it very difficult to insert the plugs into the sign contacts myself, and to my thinking it appears that the plug is never totally inserted when it is successfully attached. At the risk of breaking the sign while trying to insert the plug, I carefully attached just one corner of the plug into the contacts (this is suggested in the enclosed instructions as well) and then very gingerly wiggled the rest of the plug into the contact. Make sure you do not hold the sign at the top in doing this or it will bend. Grasp the sign at the bottom close to the contact points. This is also mandatory if you have already attached the supports to the sign; otherwise the bending will snap off the supports that you have glued on the back of the sign. I love these signs but have to admit that putting them together is a delicate task because of their fragile nature.