No, it wouldn't be that hard. A good portion of that dent is more of a "push in" anyway, as opposed to an actual hard dent. If you could get between the trunk floor and quarter panel with a board, you would be able to pop some of that back out. Using anything small or pointed to push it out is going to make ding marks. The one real crease that you do have is that one right below where the paint is popped off, and that one is going to leave a mark when the rest is straightened. But you may be able to get to that area from inside the trunk so you could massage it flat with a hammer on the outside and a dolly on the backside. For the dent remover, you need to remove all the paint where the dent is so you can braze the studs onto the panel. Do not use the cheap "drill a hole and screw in" type of dent puller. Those leave an extruded, dinged up, holey mess behind.

 

I agree with Camaro69. That might mostly come out with carefull use of some internal pressure. If it was mine I'd try a 2x4 cut at a pretty good wedge angle inside the trunk to work it out. If it's cut short to fit inside the trunk it can be tapped in with a hammer to drive most of that dent out. At some point it will pop out, and then dollies or more wood cut to fit can be used to work the remainder out.
You wont save the paint, as it's already chipped, but it will be very close and i doubt it will need much filler. I can give you a hand if you decide to do it, but not until after the first of the year, as it's pretty busy around here until then!-Vall