Focus ignition coil.

 There are only four screws holding the coil in place.

 I just wrapped a bit of insulation tape on three of the HT leads so not to mix them up when I put them back on the new unit. Detached the side lead removed the four screws and took the unit off.
I attached the side lead to the unit before mounting it, I thought it would easier to do loose, screwed the unit in place replaced the HT leads and started the car bril.

 The only tools needed> a screwdriver with a star bit and/or a magnetic screwdriver so not to lose the screw when extracting them.

After repairing the crankcase breather pipe there was still a dead spot on the acceleration. I don't know why but I thought it might be the coil that was going down (years ago when car engines had moving distributors and rota arms and points we prepared for winter by changing the spark plus and points) and the coil is about as close to this as I could imagine.

First I tried to take the old one off just to check if there were any snags. Apart from the screws holding the coil in place being over tight, it was an easy job. So of I went bought a new one and fitted it, the dead spot has gone!