Expired passport, but living abroad.....seeking best approach to renew

As the title states, my Italian Passport expired in 2015 (I am also a UK National and a Permanent Hong Kong resident).

Does anyone know if I can simply (1) register with AIRE using my expired passport (2) then change my residency to HK with evidence and then (3) get a new passport?

Hoping that it is as logical as that!

Thanks!