Arm rest problem!!

[Pattycake]

I have a stock 07' Yaris Sedan. My arm rest doesn't stay down..as you can see in the 1st pic.. its opened and it always pops back up when i push it down. The problem is the hook on the top part doesn't grab the bottom part because the top part is pushed out and it stays like that like a mechanical umbrella that wont stay closed all the way. the 2nd pic, you can see the arm rest has a little gap.. thats what i need to somehow push back in and make it stay.. the 3rd pic is how the gap is supposed to look like..nice and tight. with a teeny gap. so the hook for the top part of the arm rest can grab the bottom. can anyone please help me with this situation? thanks!!!