pretty self explainitory I don't know if its just me but how do download it doesn't tell me and i didn't give me a pop up so please help!

Download what exactly, the game or the pre-order dlc? Don't think you can download the game itself on the 360 as of now.

Do you mean how to install the game on your console HDD? If it's this, just look in the user manual.

Press Y on the game disc icon rather then A via the dashboard and select install game etc.