You have to take out the fender liner. What's the problem? Jack it up, take off the wheel and five minutes later you're there. It's just held in by a few clips and screws.
To tighten up the antenna base to the fender you have to pop off the rectangular cap from the base to access the four screws that fasten the base to the fender.
well mine must have been replaced with aftermarket cause I can see the 4 screw holes but there is no screws. it seems to me that there is a single center stud. so I guess I will have to take the inner well after all. I was hoping I could get to it through the door opening but no dice