Photoshop a face into another photo

I have two photos of kids. One looks good on one, one on the other. I need to merge them i.e. I need the face of the boy from photo 2 to be photoshopped into the other photo 1 with a smiling girl. It needs to be done very professionally and seamlessly. His head should be turned as in the original photo 1. I need the file back in jpg and png. As a second step after I accept the face change, the photo should be turned in a way that the door edge is straight vertical. Then again a file back in jpg and png.

What I attach is only a low resolution sample. The actual work needs to be done on original high resolution file.