You ask for the impossible OP, for God is necessarily possible.
To prove something's non-existence can be rather simple (despite this wild claim that says proving the negative is impossible). You prove its impossibility. For instance, I can prove, with near certainty, there is no elephant in my house because it is impossible given the space available and what otherwise exists therein.
Unfortunately, God cannot be shown impossible. Something is only impossible if its existence is contradictory with something. Contradictions exist because of the conflict of limits (e.g. an elephant's physical existence entails it is limited spaciotemporally and can be contradicted by the existence of some other physical thing in its place). God (of the philosophers), by definition is the I AM or the infinite being. Infinite means to lack limits, therefore God cannot admit of contradiction, and therefore is necessarily possible.
To prove something's non-existence can be rather simple (despite this wild claim that says proving the negative is impossible). You prove its impossibility. For instance, I can prove, with near certainty, there is no elephant in my house because it is impossible given the space available and what otherwise exists therein.
Unfortunately, God cannot be shown impossible. Something is only impossible if its existence is contradictory with something. Contradictions exist because of the conflict of limits (e.g. an elephant's physical existence entails it is limited spaciotemporally and can be contradicted by the existence of some other physical thing in its place). God (of the philosophers), by definition is the I AM or the infinite being. Infinite means to lack limits, therefore God cannot admit of contradiction, and therefore is necessarily possible.