Id tell him to turn it in for proper destruction.
And not to buy another gun. That level of rust almost assuredly has pitted the metal and if you have pitting on any important parts its more than likely not safe to fire.
How do you neglect a gun like that? I mean if it was a $80 beater shotgun in your truck toolbox then that's one thing. But a smith and Wesson bodyguard is another thing.
1. Take gun apart.
2. Wet all parts with a good penetrating oil.
3. Let set for 24 hrs
4. While waiting beat the idiot that did that with a ball bat
5. Use a Chore-Boy COPPER pot scrubber. Wet it with same oil, rub gently by hand.
6. Gun will turn coppery color. Wet with some MORE oil, rub with clean soft cloth (color comes off)
Blueing is probably shot. Above will make it look BETTER, but only a reblue would make it look GOOD.
Repeat step 4 as needed. Best penetrating oil made is KROIL, made by Kano labs. Google is your friend.
I hate seeing it like this because I have one just like it. It's an awesome gun and shoots great for its size.
He said he left it in his trunk in the nylon case it came with. And condensation must have gotten to it.he literally walked out to my car, handed to me, and asked if it could be fixed. That's when I snapped that photo! Lol
0000 steel wool with a 50/50 mix of Kroil and Shooters Choice bore cleaner. Remove rust wipe the pistol down well I'd then treat with Eesox or Miltec-1. Check internals for Rust (springs etc) R&R what's needed.
Learn to wipe down daily after each carry. Never store pistol in holster when not in use. When storing firearms in safe or lock box have a humidification dryer device present even simple clay packs
You can have a smith refinish the pistol also.
Chit happens, but it is easy to prevent with a little daily care.