In the end, the answer is that you do it. To quote Nike.. "just do it".

Don't talk about how you're going to do it someday.
Don't write on the internet about how you're thinking about it.
Don't make an appointment to meet some throwers at practice and then discover that you're busy.

Do it.

You don't have to throw Pro level to do it. You don't have to squat 400 pounds. You don't have to have the perfect nutritional plan. You don't have to have the perfect training regime written up for you by the world champion. You don't have to have custom-made equipment welded up just for you.

You cobble some stuff together. You get some rocks. You figure out how to make some weights and hammers. Then you go throw them. If you can hook up with some other throwers, then you do that and if you can't, you can't. After a few weeks or maybe a month of that, you pay your money, go to a Games and throw.

Talk is cheap and writing on the internet is, in the end, bullsh**. If I had a dime for every guy who wrote on this board or contacted me via someone else saying they were "thinking" about throwing at the Games, I'd retire. The answer to the question is quite simple. YOU DO IT.