Dissamble the hinge itself

Hey there,

I've got a MacBook Air and it's hinges are broken (actually just one of them).

I used the iFixit guide to tear the whole macbook down. Now i've got both hinges on my desk. One was already broken, the other one is cracked.

Since I'm waiting for my new hinges (just the small parts which are mounted at the body - not at the display) i'm wondering how to get the cracked hinge of the "shaft" and how to get the new ones back on the "shaft"?

Edit: Just to get this straight - i've already been at the apple store and got told the additional warranty for the hinge problem is exceeded..