I would really appreciate if somebody who has changed the clutch with the alfadiag could write a rough ten step guide of the process.
Oooh, a challenge!
1. Depressurize system with AlfaDiag
2. Remove battery, battery tray, undertray
3. Lower rear and near-side engine mounts to allow access to the finger bolt
4. Remove actuator and set aside (no need to detach hydraulics to/from pump)
5. Remove driveshafts and starter motor
6. Remove gearbox
7. Remove clutch and release bearing
8. Refit everything in reverse order
9. Adjust clutch rod length
10. Recalibrate gearbox
Smaky is promising to do a complete pictorial guide over on alfa156.net (have I said this already?). I've not seen it yet though. He may have done it while he's been off work this week.
I'd really recommend you or your mechanic give him a call to discuss it. I have his email/mobile, and he's your man.
It's really just the same as a manual gearbox change, once you have the actuator off.