I can't get the back of my seat on. Every looks in tact and unbroken, Well the two clips at the bottom. I push it in at the top and gently push all the way down till i get to the bottom. I've now got to the point where i hit the area where the clips are and nothing. It will sit in for a day and fall off. Its starting to **** me off. Is there a correct way to fit theses or am I missing something?