how do i make a head shorter...and straight

hi
id like to make a head shorter vertically, and position it so that it is not on a tilt.

is there a way o make it shorter besides free transform?

i dont know how to use the ruler guideline to reposition the head..can you explain it to me

you can use the crop tool and check mark 'perspective'. when you draw the box make sure you have a reference point on something that should be vertically straight.