This side needed a slightly shorter socket extension. Access is tight.
Plug number four (blurred image!!)

Five.

Six.

I cleaned the plugs, but left the gap well alone. I made sure that the threads were clean and refitted with a smear of coppaslip.
I also smeared Coppaslip on the manifold setscrews. Keith advised me that the manifold gasket is usually OK to re-use. If you wanted to change the gasket you may have to liberate the inlet manifold some more to get enough room to change it.
The plug caps come off with a sharpish tug, and relocate with a muffled "pop".
And that was it. An afternoon's work, and the Roadster fired up straight away as usual................