The Alfa GTV6 Distributor Primary Lead Wire is plugged into the side of the distributor housing with a special plug. Don't just yank this plug out! There is a wire spring clip that needs to be carefully removed. The spring clip is similar to the ones holding in the temperature sensors and injectors.
Be careful when unplugging this connector because it can be delicate and brittle after all these years. One of the larger issues with a classic car like the GTV6 is trying to find uncommon, but important pieces like this, so tread lightly!
Note, I have an early car with a 2-wire connector. Later cars using the Bosch EZ-L digital electronic ignition system have a 3-wire connector.
My pick is pointing to the wire clip that needs to be removed. This could be covered with grime, so you may have to look closely for it.
You can see me holding this U-shaped wire clip. It fits into the two grooves in the black connector attached to the distributor.
This is the signal or primary wire unplugged from the distributor. The tabs on either side get locked in by the wire clip. A good tip I use is to place some white paper towels underneath something I am working on so if you drop a tiny clip you'll find it and it won't fall into the engine compartment never to be seen.