Loosen up all the bolts under the hood and the one or two you can see with the door open then close the door and run a strip of masking tape on the forward edge of the door as well as the fender (to prevent paint chipping) then insert something in the gap and gently pry the fender forward to increase the gap then re-tighten bolts. I have used an autobody spoon (resembles a cooking spatula) many times for this. This also works to make the door and fender flush if the edge of the fender is sunk in slightly.
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