Uh-oh... I got a leak

[Cholo]

I was on my way to check out in apartment today when it started pouring rain pretty hard for a good 20 minutes.   I noticed a little drip of water out of the corner of my eye and after feeling around, it looks like my windshield has spring a leak.   Looks like the seal in the top "corner" of the passenger side is leaking. 

Anyone know the best way to fix this and about how much it costs?  Thanks