popping the dent out is the easy part. the hard part is getting access to the right spot and being able to push it out. i had to be really careful and find a way to stuff the screwdriver at an angle because i have the window motor in the way so i did not have direct access.
in your case i think the quarter would be fairly easy if you take the tail light out and get some access from the trunk as well that will help you tremendously, but for the fender i don't really think you can do much without taking it off the car. also if the dent is on a crease it will be really hard to get it back to the way it was.
hope it all goes well for you as it did for me and if you need any help let me know