Faema marte/mercurio upper group gasket

Faema marte/mercurio upper group gasket. and how do you need to replace the old one with a new:

• Unscrew the 4 bolts on top of the group;
• pull the group assembly out of the brewing group;
• if you look inside the inner ring has a gasket, remove the old gasket and replace it with the new one;
• do the above things the other way around