How to submit game logo later to a new game?

I have submitted a game but I did not add the game logo right at the beginning. How can I add the logo later?

Btw, the game addition submission has already been approved.

Thanks.

If a page has no images in its gallery, the first image added will become the default. You just need to upload one to the gallery.

@dungbootle: Ok, thanks. I will try this.