What Dave said. You pull the top up and forward, then align the pins with the holes in the windshield surround. When you lock the handle, the top mechanism slides forward locking the pins into the windshield frame. All is good.
Something to watch out for.....when you put your top back up, make sure the pins don't hit the rubber seal around the window. If the seal gets a little tear, it will leak and they are virtually impossible to find replacements....:yesnod:
I just changed a window regulator in mine not to long ago: And I noted all of window adjustments. They are really easy to adjust on these cars. So if you have a leak against the window seal, you should be able to take the door panel off and make necessary adjustments in about 30 min max.
Edit: Assuming you mean an actual leak that that is letting in rain water or a lot of howling from the wind. If you are referring to the small wind sound coming from the rear of the window, typically this is just a convertible thing and not an actual leak.
My '06 was purchased with the rubber seal pierced by the two top pins. Does not leak even when going through car wash...but sure does leak through side window seals!!! Anyways, I went to the local Chevy dealer to see about ordering a new top to windshield/sideglass seal. Even tho it is a first year car, I have to find a number on the convertible top! Seems different seals were used? Cost will be anywheres from $250 to $400! Holy freaking cow!!! Found a place online that says $281 for an '07 seal. Still, holy freaking cow!!! Taking car back to Chevy dealer in a day or two in order to find top number. Will probably bite the bullet and order a new seal next month or in October. I think the two little round seals on the top in the back around the pin that snaps into the trunk lid, have to be purchased with the triangular metal piece for around $27 each. Going to check on all the seals just for the heck of it. Probably cheaper to buy a new car...