At the 'Password' screen enter H.I.Z.Z.O. To unlock Shawn Corey Carter the American hip hop artist and businessman who is better known as Jay-Z the husband of Beyonce Knowles and owner of the New Jersey Nets.
To get the level 3 achievements make sure you have a good lv. Three superstar for the acheivement you want.(eg. Steve nash=lv.3 scorer, shooter playmaker) Always press LB and rotate the right stick. You do a good trick move and should get the achievement. Go on a big scoring run and get in the zone. Hold LB and rotate right stick to do the move. You should get the acheivement easily