A choke and kill system, and a method of adapting a low pressure drilling rig for use in a high pressure application are described. The system has a low pressure stack and a high pressure blowout preventer stack fluidly connected to the low pressure stack. A choke is fluidly connected to a low pressure choke line of the low pressure stack and is connected to a high pressure choke line of the high pressure blowout preventer stack. The choke is adapted to reduce the pressure from the high pressure choke line to the low pressure choke line.