You said it yourself - pics are needed, the answer could be anywhere from Bondo to frame machine.

 

Go to a wrecking yard and tell them you want ANY piece of body metal, whatever is the cheapest piece they have laying around.

Take it home build a little frame to screw it down for stability to keep it from flexing (like how it will be when working on a piece bolted to the car), sand it down, practice using body filler, sanding, and painting it. Then when you feel comfortable with the results do the one on the G. Might take a couple practice runs with the bondo before you get the sanding down, best advice I can offer is to use a large sanding block. I usually make my own from a piece of 2x4 I ran through the tablesaw to get a perfectly straight edge on, cut it down to like 18", concave bends in the sheet metal are the hardest but as long as you're doing work on the convex part of the panel it's REALLY hard to screw up the bodywork. Biggest noob mistake is not sanding enough and having a slight rise.

You can google up different kinds of flapper wheels and such that people use for stripping paint/primer from their vehicle, don't overthink it just grab whatever you think will work for you on your angle grinder.

WEAR SAFETY GLASSES PLEASE and a dust mask for grinding off that old paint, bondo makes your skin really dry for a couple days so I like to wear disposable nitrile gloves now, if you don't feel comfortable with the paint matching then just get a quote from the most reputable bodyshop in town for paint/clearcoat.

 

 

Good luck . Thanks cleric for the detail.