Many, many, many, many thanks for your help simargl.
Your help was invaluable.
But the system doesn't boot
First it complained about not being able to find archpup_132.sfs.
Then I renamed alpha_80.sfs by archpup_132.sfs and it seemed like it was going to boot up but then it got stuck in "performing switch-root".
Then I even renamed extra_80.sfs by archapps_132.sfs but it still got stuck in switch-root.
So, either I missed something or it just isn't as easy as you had thought it would be
I love alphaOS but without proper cpu-fan control it will kill my old laptop with temperatures higher than 90C when it should go around 45/50C.
What do you think?