Many thanks Laura.
I went today the office in Paseo Sant Joan, here in Barcelona.
For the possible future benefit of someone in my position I will provide the details of what I found out today.
They gave me the following link to make an appointment:
www.mpt.es/servicios/extranjeria.html
And also this link to a form which I need to complete:
http://www.mpt.gob.es/servicios/extranj ... s/EX16.pdf
Also I need to bring the following:
a) My current Regimen Comunitario
b) My passport (Australian)
c) My marriage certificate issued no more than 3 months prior to renewal application and officially translated.
d) My wife´s passport or national identity card.
e) Three recent colour passport size photographs (on a white background)
f) Proof of payment of the fee for issuing the card (Bank-stamped Modelo 790)
and the earlier mentioned application form.
Then appear at the organised appointment, provide the above mentioned documents and then wait for a (hopefully) positive answer within 3 months.
Thanks again to everyone who responded and if anyone has questions that pertains to this, don´t hesitate to post and I will try my best to help.
All the best.