[yorkie_chris]

Never removed plugs before? Good time to learn how then.

Coils live under the tank, LT leads go from ignitor box to the coils... HT leads go from the coils... to the plug caps ... to the plugs.

Pull caps off, unclip a wire from each coil, remove spark plugs. When it's cranking with no oil light, then fit new plugs, refit plug caps, replace wires to coils. By the time you've done that the oil level will have settled and you can recheck it.