one go about proving...? anything doesn't exist? How would you go about proving pink dragons don't exist? Would it be the lack of evidence for pink dragons existing?

Please tell me how you can prove something doesn't exist other than lack of evidence for it existing.
@imrod
How am I being silly? People say we can't prove god doesn't exist. We don't believe one exists because there is no evidence for one existing. I am asking a honest question. How do you prove something doesn't exist other than lack of evidence for its existence? I'm trying to show people that there is no other way to prove something doesn't exist other than lack of evidence for its existence. If the Judao-Christian god existed, there would be evidence of it. There is none for him or any other god. That is why we are atheists, lack of evidence.

@people answering about god
I'm not asking a question about god. I'm asking you to show me how you can prove pink dragons don't exist. Leave god out of this.