Five images need to be edited

Five images need to be edited 1) In 2 image you will have to change multiple faces (from other image), background and dress color so that image should look original (not copied from anywhere) 2)In 3 images you need to change the background 3)Mostly background should be classroom(you need to find out the classroom background ) or my company banner should be there 4) You need to adjust the skin tone and all that