Before doing this you'll need to remove the top panel of the machine, turn it off and close the inlet water line if direct plumbed.
Tools required:
flat head screwdriver
angled pick
1.5mm angled allen key
adjustable wrench
Alex Duetto: Expansion Valve Seat Cleaning / Installation
Below is a guide on cleaning and installing a new expansion valve seat on your Izzo Alex Duetto espresso machine.