To summon a superman mob all you have to do is tap the ground with a stick. You already have the ability to fly and super punch(tap the ground with your fist.) The superman mob has close to infinite health so it will take some time trying to kill him. He isn't hostile so he won't attack you. Just apply the .js and the texture pack and the mod should be up and running. 
The item IDs for armour (Superman suit) are 306, 307, 308, and 309 (iron armour)

-KamariTM