Here is a couple of examples of windshield trim tools. There are other examples out there as well.
The big thing is to NOT GET IN A HURRY, when removing trim!
It is not uncommon for trim to be glued in place (with sticky rubber like material), so after they are unclicked, you still need to gently pull trim off (using a knife to cut the rubber strings, helps).
Marking the back side of trim as to which piece goes where, is helpful - if not reinstalling trim right away. A damp paper towel and a fine tip Sharpie works great for this.
Once trim is off, clean out all of the dirt/mud that is remaining (a water hose and bristled scrub brush helps). Then look for rust, particularly in area by the clips.
If “rust through” is present, the only fix is to fix it correctly – and that may some work/effort.
If “rust through” is present and is only patched over – the leak will come back very soon and will be a lot worse than it was before (and harder to fix)!
BudW