Remove the 4 spark plug cover bolts using a 5mm allen key.

Remove the spark plug cover

Clean loose dirt from the coil area to prevent it from dropping into the spark plug holes. An air compressor or can of compressed air would be useful here.

Remove the 4 ignition coil bolts using a 10 mm socket or wrench.

To unplug the ignition coils, you need to lift them out of the engine slightly. First, pull up on the coil to separate it from the spark plug.

Once the coil is high enough to rotate without hitting the valve cover, you can disconnect it from the wire harness. Remove the connector by pressing in the release clip, wiggling it loose from the coil, and rotating the coil away from the connector once it's loose.

Remove the coil from the car.

Again, clean loose dirt from the area to prevent it from getting down into the spark plug holes. Use compressed air.

Using your spark plug socket, extensions, and ratchet, remove the spark plugs.

With the iridium and platinum plugs I linked to above, don't use the traditional wedge/coin style gap tools. Fragile tips will break, so you have to use the feeler or wire style tools that have tools for bending the side electrode without contacting the fragile iridium center tip.

The new plugs come pre-gapped, so you shouldn't need to adjust them. This step is just to assure that they are correct.

Using a feeler gauge, check the gap on all of your new spark plugs. Gap should be set at 0.039 - 0.043 in.

Install each spark plug. Do not use anti-seize on NGK spark plugs. NGK (and most others) use a special (Trivalent) plating that does not require anti-seize. Also, anti-seize will affect the torque rating used to tighten them.

My favorite trick to keep from cross threading a plug into the cylinder head is to use a rubber or silicone hose pushed onto the end of the spark plug. The hose will allow you to more easily feel the correct thread engagement of the spark plug then using a wrench would. And, ideally the hose won't grip the plug as strongly, so if you do mis-thread it, you won't be able to tighten it enough to cause damage to the cylinder head.

Tighten each to spark plug using the method described in NGK's instructions.

• New Plugs: seat the plug, then turn 1/2 to 2/3 of a rotation (180-240 degrees).
• Reusing Plugs: seat the plug, then turn 1/12 of a rotation (30 degrees).

Torque is critical to spark plug functionality. Too loose and it won't dissipate heat properly, too tight and it can break.

Slide the coil pack back down into the spark plug shaft and connect the wire harness to the ignition coil.

You may wish to add dielectric grease on the coil boots where they slide over the spark plugs.

Push down on the center to make sure the coil snaps onto the plug completely.

Re-install and tighten the bolt for each coil using a 10mm socket.

Test the car before going any further. Start the car once you've changed all the plugs, re-installed the coils, and bolted the coil packs back onto the valve cover. If the car starts and idles fine, shut it off and finish the install.

Install the panel and tighten all 4 of the 5mm allen head bolts.

Celebrate.