The modern Mini Cooper has a fuel-injected engine. This engine receives fuel from the gas tank via the fuel pump; as a result, the fuel pump is critical in the operating system of the engine. If it should fail, then the engine won't receive fuel and therefore won't be able to run. To fix the issue, you need to remove the fuel pump from the gas tank so that you can replace it with a new one.
Open up both doors on the Mini Cooper. Slide both front seats forward using the adjusting handle on the bottom of the seats.
Unbolt the bottom of the rear seat using the 3/8-inch ratchet and socket, taking off the bolts on the front edge of the bottom of the seat and the two in the gap between the top and bottom of the rear seat. Take the bottom of the seat out from the back of the Mini and move it out through one of the doors.
Unbolt the access plate for the fuel pump using the 3/8-inch ratchet and socket and unplug the wiring to the plate with your hands.
Remove the outer ring on the top of the gas tank with special tool 16-1-020. Pull the fuel pump and fuel level sensor assembly out of the gas tank.
You can find tool 16-1-020 at your BMW/Mini Cooper dealership. If not, you can also check at online tool suppliers such as Cornwell Tools or Matco Tools.
Never smoke or have an open flame nearby while you're working on the fuel system of a vehicle. If you do, you risk causing a fire and damaging yourself and the vehicle.