Yeah you can do that. All you do is find a bat and wedge it in there on either side that fits best. The idea here is to take your time and not try and get it all in one shot. You also wanna do it on a kinda wamr day so the paint is warm.
The bat will be between in the fender well and tire. The end sticking out from the fender points down to the ground. Firmly grab the bat with two hands and roll it along the tire and working it into the inner fender back and forth real slow. Turn the bat and roll it back and forth to work that iner lip.
If you try to go too crazy you can make ripples or waves in the fender lip... so take your time
Andy FYI all. I got my stuff on... and my 45 offset works great with the JICs