Found an adaptable image to add it too thanks to the morgue
step 3 of 5
Do the initial combining and editing to size and adapt to angle etc.
step 4 of 5
Alter the profile a little with the nose. Resize the hat and do a lot of shading of face from shadows to highlites trying to have it fit in with background and clothes.
step 5 of 5
That pretty much is it, but a lot of blending details. ; )