Complex sentence: Trays are performed when a fast-food tray is placed under the rear tires and then engaging the handbrake and then by going foward and turning the steering whell so that the the rear slip angle of the car is greater than the front slip angle.
Split into simpler sentences: Trays are performed when a fast-food tray is placed under the rear tires and then engaging the handbrake. After this is performed the driver goes foward turning the steering wheel so that the the rear slip angle of the car is greater than the front slip angle.