Pointers that are missing in this for anyone watching: 1. They make magnetic spark-plug sockets that hold in the plugs, so no "tube" req'd. 2. Clean the ignition coil retention bolts, as well as the inside of the ignition coils, with WD-40 to clean the crap off. 3. Put a small dab of "Anti-seize grease" on the threads of the plugs. (they actually mentioned this) 4. Find the correct torque specs for the plugs and use a torque wrench (if you have it) If not, snug it up real good. (they actually mention torque spec) 5. Put "Diametric grease" on the inside of the ignition coil. Not doing this means it may not contact the plug correctly or and misfire.
Thanks for your comments, it's always great to receive feedback. Here's a couple of things about the points you raise: 1. The 'tube' is used during plug fitting to allow the threads to start without the risk of cross-threading. The idea is, if the threads don't start engaging properly, the tube will slip on the plug insulator body, preventing damage. 2. Yes, the bolts need to be clean, same as they do whatever you're fitting. Same goes for cleaning - WD40 is great for chasing out any moisture. 3. As you point out, we do mention anti-seize grease. 4. Torque wrench settings for the plugs vary between engines and manufacturers - best to buy the relevant manual. 5. Some manufactures recommend diametric grease on the cap contacts, some expressly forbid it - check in the manual.
