LEGO Star Wars Hints

Go into Jedi Battle and walk along the level until you get to the elevator. Change to a person with a gun, shoot the target to activate the elevator, but don't stand on it. Instead, stand underneath it and wait. When it comes down, it should push you underground. To get back above ground, just keep jumping.
Note:Keep walking or you'll fall. If you fall too far, you'll die.

Have Jango and Grevious on Level General Grevious and go to the bridge where Grevious jumps off in the beginning and press X with jango to make him hover then tag other player, change other player to grevious, and push Jango off the Bridge. he will FLY under the bridge!