Granny Smith

I am not a mechanic but want to remove the plastic cover so I can fix a spot of rust that has developed at the lower left corner of the light on the right side of the hatch. I have removed the little cover inside & the two nuts and the plastic pieces they hold but I'm not sure how to proceed from here. I am told that I am a strong woman and I don't want to apply brute force and break anything.

I have not disconnected the bulb because there is nothing wrong with it and I am hoping that I don't have to because then there may be. I'd like to do the rust repair tomorrow because rain is expected the next day.

Please give me some simple to follow directions.

Thanks!