In order to do this you will require 3 replacement injectors. See here for details on the type of injector available. Before you start, take a precaution: disconnect the battery before starting.

Start by removing the following:

• Top intercooler pipe from the throttle body
• Crankcase breather from the back of the throttle body
• Oil breather from the front of the throttle body
• Vacuum hose from the fuel pressure regulator
• Throttle body connection
• Inlet manifold vacuum pipe
• 2x Fuel Lines
• 1x Fuel Vacuum
• IAT sensor connection
• MAP sensor connection

Under no circumstances put the key in the igniton. Turning it to position 1 will spray neat fuel over the engine when the fuel pump primes.

Use a HT lead removal tool to free the leads on the three spark plugs. Do not use anything other than a genuine tool as you risk breaking the leads. Once free, you will be able to see 2x E10 bolts holding the fuel rail to the inlet manifold. Loosen these taking care not to drop them down into the engine.

There are 7 more E10 bolts holding the manifold in place. You may need a universal joint in order to access these as they are quite awkward.

The inlet manifold should now be free to remove from the car.

Carefully tilt the fuel rail down on the right with a small pot in order to collect the fuel that is still sitting in there. Swing back the whole rail. You can now unplug the injectors from the rail and their respective coil.

Replace with the new injectors. The ones shown in the picture are the Brabus 74kW ones.

Reassemble the manifold ensuring that all lines, pipes and leads are reconnected.

The torque settings for the fuel rail to the inlet manifold are 8Nm.
The torque settings for the inlet manifold to the cylinder head is 12Nm, then 10Nm respectively.