The skip begins by boosting off of this suspiciously ramp shaped box. There is no death zone in the pit behind the box, but you can Elevator out of it.

Once on top of the map, you can Wall Climb at the spot shown in the image (it does not need to be boosted). From there, you can get on top of the structure and skip past the comparatively slow tunnel. 

Return to the track through either Air Boosting, or Drop Storage to gain speed and get ahead. If Air Boosting, aim for the right if you don't have enough height to reach the upper left structure.