#4 is on front driver's side. Pop engine cover off by pulling up then towards the front. Take the intercooler hose off, hose clamp in front and wire snap in back. To release the wire snap, practice up front near the hose clamp you just loosened. Use a pick or flat screwdriver to pull up on the wire while putting back pressure on the hose. Wire will remain in the clamp assembly. After the hose is removed, pull up the rubber sound deadening and put it on top of the fuse box for a knee pad, you will want to get comfortable! The glow plug wires are connected to long stems with flat tops. Mine had a blue assembly mark on them. Look near the top of the motor, above the injector fuel rail, down in the crevice. If you've ever hunted mushrooms, it's like finding that first one. Once you find one you will see the other 2. #4 & #5 are not too bad, #6 makes my back and knuckles hurt just looking at it. Pull up on the stem, might take a lil force. I now recommend you blow the crevice out with compressed air to remove all the crap around the hole your about to open up, hopefully. Blow then soak with your favorite penetrating oil. That felt weird to type. Get a 1/4" drive ratchet, extension, and 5/16" deep well socket. Mine broke loose easily, then fought for its miserable life the rest the way out. Like I said, get comfy. Spray, soak, out as far as your nerves will handle, back in till it reaches a loose spot then spray, soak, out...repeat. took me 2 hours. I walked away a couple times. Be patient and careful, it's actually a very easy procedure. Just keep looking at #6 and be thankful