piece of piss funky, coilpack connector off, coilpack out, sparkplug out, replacement in (turn it 1 full turn anticlockwise first to prevent crossthreading) coil pack on and reconnect. The cables for each pack are limited so you can mix them up, the last one requires a few 10mm nuts off and a torx head screw (the right sized flat head will also do) to get the n249 reservior off first.