This is simple then. Prove it wrong. Prove God does not exist.
Atheism is an unfalsifiable, position. Which, in logic is already a fallacious claim. You cannot make an argument for what isn’t. Therefore, you can only try to debunk the arguments that do exist. They are out there, prove them wrong. Find their error and you will have debunked an argument.
But that doesn’t prove atheism. Atheism cannot be proven, theism can be. It’s simply a much better logical position.