Got hit while parked

I've bought a 'dent repair kit' from Amazon for £30, which has a selection of pieces to glue on for some slide-hammer action and have some aircraft grade filler to try to sort this out. What are the problems in going to encounter when trying to sort this one?

Hopefully if I can make it look something like it, I'll just get the repair area sprayed by a garage. If not, do you guys have any recommendations for how to DIY spray a 'home repair'