Audis and many newer vehicles utilise coil packs instead of one coil that powers all the cylinders. Coil packs are more reliable because if one coil pack fails, then it only affects that particular cylinder rather than the whole engine. Coil over plug ignition systems don't use spark plug wires like traditional ignition systems and are therefore very straightforward in replacement.
Remove the coil pack cover with a ratchet. The cover is held on by six bolts.
Unplug the coil that needs to be replaced.
Remove the coil with a ratchet. The coil is held on by two 10mm bolts. Once you have the bolts removed, pull firmly and the coil will come out.
Install the new coil and tighten it with a ratchet.
Reconnect the coil connector.
Attach the coil pack cover back onto the valve cover and tighten the bolts with a ratchet.
If the coil pack is stuck in the cylinder head socket, use a flathead screwdriver to pry between the valve cover and the coil pack to release it.
Wear safety glasses to protect your eyes from injury.