Kung Fu Rider

This can easily be done in the Skyscraper Free mission as there are a lot of high points to jump off of. Here's a way to get to a high area from the beginning of the mission. Take the right path at the intersection in front of you. Then take a left at the next intersection and jump off the ramp to get above the stairway roof. If you can't make the jump, increase your boost bar so you can go faster. While on top of the stairway rooftop, follow the rooftop to the wall of the building and go right. Around the corner to your left you should see some scaffolding you can jump over to, jump onto it and go left. Jump and grind over to the next platform and follow the wall to the right, you should see a cable you can grind on to some other high areas. I recommend jumping off the cable while grinding up to the other high area to get you some more air time.