No offense man, but do a forum search. This has been answered about 2 dozen times. In fact, I believe there's one such thread still on the front page.
I'll answer you, though.
![Stick Out Tongue :p](./images/smilies/)
You know that jutting out, perpendicular bar on the right hand side of it? Well, you have to run into that bar, and thus move the entire locking mechanism to the right. Try it from a bunch of different angles... took me about 5 minutes of constant running into it to get it done. Good luck.
EDIT: Yeah, still on the front page,
Here.
EDIT again: Yeah, another one on the front page,
here .