I rebuilt a head using a drift made up by my local engineering shop (who skimmed the head and re-cut the valve seats for me). Head needed to be heated up in the over first as there is no way that the will go into a cold head. Sticking the guides in the freezer will also help. Without the Alfa tool, I had to tap the guides in from the valve seat end. Otherwise you will break the lip where the stem seal fits.
I may still have the head in the garage somewhere as the car ended up as a doner for my current 'wagon before it was all assembled. Let me know if you are interested as I also have a full timing belt kit and a set of cam locks that I no longer need.
"When you sit in a Focus RS or a Golf R32 itís like sitting in a commercial for Lynx aftershave. When you sit in an 147 GTA itís like sitting in a Venetianís hand-made suitcase." J.Clarkson 2003.
Current fleet: 156 Sportwagon jtd 16V (facelift) 2.4 Spider, Leon Cupra SC
Projects: Spider S4, Matra Murena 2.2