Finally got the top off.... and found rust... help!!

[my71gmc]

Well, after over a year I finally got the top off my Jimmy this past week. It is great driving it like this, particularly when we get good weather in Minnesota.
The problem is I found this rust on the upper windshield frame behind the seal. I am hoping others have fixed this and can give me some pointers. This is an original Jimmy from California with hardly any rust, so to find this was a bummer... Thanks for any help or advise!!