94 Eldorado, and a 99 ETC
Actually I don't think you have to unscrew anything when changing the wires, unless your changing the plugs too. If you are changing the plugs too then you would need to buy a gapper (not sure of the correct term but thats what I call it) from the locol auto parts store. All the wires are just snap-ons. You do want to twist each wire connection first before you pull them off, because if you don't you might peal the wire cover from the wire. There is a plastic wire cover going next to the beauty cover, the top of the plastic cover is held on with plastic clips on the sides.