Buy the Wingsuit through the storage that's in all the Trading Posts or from the Traveling Salesman that are walking around the map for a cost of 25,000.
Fast Travel to Khilana Bazaar which is directly east of Banapur (1st Trading Post you find in the story).
Go out of the building and turn right and go up the hill to find the Buzzer (Helicopter).
to get in and then
to get altitude, while pushing forward until you see a large building below you. By this time if you have kept your finger on
you will hear an alarm.
As the alarm goes off press
to jump out of the Buzzer then quickly press
to use your Wingsuit. Aim for the water that you can see in front of you and glide as far as possible. You don't need to use the Parachute as landing in water does not kill you.
Once you hit the water press
to get the Map back up and repeat.
It took me about 10 minutes and 5 or 6 jumps. Enjoy