A couple notes from when I did my spark plug change.
1. I believe the Bentley manual did this on a PWG (pre-2014) 335i. You will have an additional step for a EWG car which involves undoing 1 Torx screw to move a bracket out of the way. It is required to access cylinder #5.
2. You may need to locate a inverted Torx socket to remove the one-time strut bolts. The regular socket equivalent measurement is 9/16th inch. I ended up removing it with a 12 point socket but you run the risk of stripping the strut bolts.
3. The ignition coil packs may be difficult to remove. It requires a decent amount of force to pull out.
4. I did each cylinder separately. For example, leave everything in place and remove components for one cylinder at a time. Less chance of messing up if you're focusing on one thing at a time.
5. You will need a special tool: thin wall socket. You will also need long extensions for it. I ended up connecting two extensions together.
