First go to the Slam City Jam vans. On the left will be a quater pipe. Go on the qp and jump up and grab the ledge as FAR right as POSSIBLE. Half of your skater should be in. Start to hit right or left and you should spin in to the ledge. If you get off your board you should start to float. I haven't tried to Under Level Glitch yet so you can try to do that.
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