Rust under windows rubber

[chipmunk]

Does anyone have any suggestions for fixing rust under the outside top rubber on the door? I noticed on the weekend that I have two bumps there which I am pretty sure are the start of some rust. I am considering taking the door apart and removing the rubber to fix it (any suggestions on how to do this are welcome) however thought I would first ask if anyone has an easier solution to the problem. I have tried to lift the rubber up with a thin screwdriver however it is very tight.