How to get rid of annoying air bubbles between iPhone case and the iPhone screen?

It's so annoying everytime I snap on the case there's a bunch of bubbles! What can I do?

Try rubbing the case and force the air out

Try to use a card to extrude the bubbles out but be soft careful don't scratch your screen or buy a new screen protective. Remind that leave no bubbles and keep it appressing your screen when install a new screen then there would no buddles when using it. If you are willing to buy a new one, you can check at http://www.accessbuy.com/search.php?keywords=Iphone+screen+protector&id=