Replacing An image.

There are many techniques to replace or swap person or any other object on the image. You can place another person/object on layer above . Person on layer above must be extracted or surounded with transparency and about same size to cover person below. Transparency around can be achieved by erasing pixels what is not wise solution or using layer mask what is far better solution.

Replacing person or object is only one step to good result. You must pay attention on lightning to match what is desired to do before even trying swap in Photoshop but also and colors or mood must match what can be achieved using adjustments and tools inside Photoshop.

Hi

If the existing person is part of a larger image, then you can leave him/her there and bring the new person in on a new layer. You might want to post screen shots so we can better advise.

~ Jane

Hi yes it can be done as you saying there are many tools in Photoshop like Lasso Tool, Polygonal Lasso Tool, and content-aware tool....regards