Photo merging

It is a present for my mother. Her father died when she was a child and they do not have any photos together. I want to frame a photo with them. The only picture I have with him is in a different light, compared to my mother’s favourite picture of herself. I want these two photos together as they are next to each other. I also want the lighting on them to be as similar as possible. I want it to look real and bring her comfort. The photo I have with him. there’s a woman in it and i DO NOT want her in the picture ( long story 🙂 )