Having done the cap/rotor/wires/plugs on my 92' 740 4cyl/nonturbo I can tell you a couple of things: Use an open end wrench (8mm if memory serves) to unfasten the cap in three places (Yes, I seem to remember three). Be patient and don't muscle it, you will only skin your knuckles and maybe strip the internal threads (A small shot of "WD40" beforehand never hurt anyone). Remove the rotor by wiggling it a bit while pulling straight back. Look at both of them. They are probably all pitted and fried like mine were. Replace with new. I used aftermarket from the local parts store with much success. I guess the brand found near me is better than what some of you are getting. Aftermarket wires were a bit hard to find near me as I have the REGINA ignition (coil wire is much different), but I found the proper AUTOLITE set and wrote down the # for next time. I must admit the new wires didn't 'snap on' as tight as the OEM, so there you go, but after a week of the heat of driving I gave them another push and they are pretty snug now. Still not like the OEM's but they're okay. Bosch platinums were used and I have no complaints at all. Those four-prong bosches are more expensive and I opted not to buy them. I use permatex 'anti-seize' compound on the plug threads (This is GOOD stuff to use in a lot of places!), but I always forget to use the dielectric grease. I should really get a small tube.