This is like trying to tell someone how to put on a sweater.
Cardigan
1. Throw your sweater on the floor so that it sits with it's "back" against the floor and the arms on top.
2. Stand with the toes of your feet almost touching the label at the neck line.
3. Bend over and put your arms through the arm holes until they stick out of the sleeves.
4. As you stand upright, raise your arms over your head and the sweater will slip onto your body.
5. Put your arms down and button your sweater.
;-)
Note: This is a variation of what is a.k.a. the "upside down jacket" and FYI, never tell a three year old to put their arms down.