Yes! After trying for a while I figured it out! The building is shaped like an L, right? Well, on the inside curve of the L, there is a cylinder on a platform. Line a short vehicle parallel to the bottom end of it, and start jumping diagonally to the space between it and your car. You should jump on the car, and then onto it really fast. Once you are on the cylinder, face the building and throw a Molotov or grenade at your feet behind you. The blast should propel you onto the roof.