you take the trim panel off and there will be a blueish plastic barrier wiht a line of black butyl all around it. When you look at the bottom you will most likely find that parts of the seal have come apart.
I've tried kneeding the stuff and putting it back on but that wont fix it for more than a week.
I just used windshield sealing bead to fix mine, its the same stuff. You'll have to get all the old stuff off, its alot like chewing gum. Once you get some of it off you can use it to pull the rest off.
Charlotte-'01 SSEi loaded. Sold at 41k. I'll miss you ole' girl.
Sandra-'08 Sonata GLS. Silverstar Ultra bulbs.