Rust hiding under wiper arm panel, and by the door hinges
 

I need help removing the metal thing that the wiper arms come out of.
The metal panel that houses the windshield wiper arms covers a canal like thing for water, on the edges of this little water thing, there is some serious rust action, however, I cannot figure a way to get that panel off so I can attack the rust in the little water run-way.

I need to get rid of all this rust on my 92 ranger because it rains a lot, and the rust holes leak water into my car. I already got a good deal of the rust on the interior, and on the corners of the cab.

please see these pictures for what im talking about

ranger pictures by swoopkev - Photobucket