According to Gilly on ShopForum, it's a fairly simple thing to do except you need an old M110 engine valve adjusting wrench to get the wires off the spark plug. It's an open end 17mm wrench that you use on a groove in the metal end, then you can pry it against the valve cover to lever off the plug wires from the plugs. Works pretty slick. A normal 17mm open end won't work, this tool has a pretty deep offset and aloows you to get in there: HAZET Valve Adjustment Wrench for M110 engine. p/n 110 589 01 01 00