Go to the left bottom train station in suburbs on your map.

Go through either of the passways, then go up the ramp with the 4 green and white ledges. In between the ledges make a marker to go back up when at top of ramp.

If you turn around you will see 3 lights. Go down the ramp and go up one of them.

When halfway up one of the 3 do a fliptrick (advanced or basic but has to flip).

Eventually after you do it a few times your leg will get stuck at the top.