Firstly don't get me wrong. I hate this song with a passion, it does make a good track to mix if u use the instrumental mixed with another instrumental.
Anyway I will break down the definition of that song for you.
I have a niece, in fact I've got loads of nieces and they all like this song. It needs to be told to the whole world, how bad this song is.
The main line of the song are :
Soulja Boy up In da hoe Watch Me Crank It Watch Me Roll Watch Me Crank Dat Soulja Boy den Super Man Dat hoe
He is refering to his penis as "soulja boy", and the term soulja boy up in the hoe, actually mean my penis is in a woman.
By watch me crank it watch me roll, he means watch me shag her. His dance moves also demonstrate this.
The main line... "super man that ho" actually means to pull out before ejaculating, and cum on the womans back then as she sleeps through the night the covers should stick to her back and she will wake up with the sheets stuck to her back like super mans cape.
Then Watch Me Crank Dat Robocop:
This means I will sex the woman very fiercly and non stop, like robocop. Robocop has endless stamina and so does he... (apparently).
Super Fresh, Now Watch Me Jock
Joccin' On dem Hatas Mang
These two lines mean he is making money off of other peoples misfortunes.
I advise going to Urban Dictionary and tracing every word. And don't let any kids hear it man.