When you start the level, blow up the silver objects on the right side. Use Phastam for the wall crate. Then build the lego pieces on the floor, pull the object down, then use detective mode with Batman follow the footsteps to the dig spot and then build a machine. Jump on the seat with

, this is the Pachinko machine:
Use

for the ball to drop but make sure it lands in the middle. To do this, aim after the first hinge or before the second hinge to time it just right. If you don't get it the first time you have to start the level again and repeat the steps above.
Note: Doesn't seem like you can get up from seat with

. You have to start level over.