Just a quick reply to thank Jamesmc for the post and confirm it is still current. I carried out the same procedure on 31st December 2014.
I found the instructions easy to follow as I know the area quite well, but here is a bit of extra detail if you don't know east Lisbon.
The road mentioned runs between Oriente station and the large shopping centre, so if you come up from the Metro or down from the train at Oriente, from the ground level you exit the station and the shopping centre entrance is opposite you. Don't cross the road but turn to the left and continue. After about 10 minutes you will see some huge narrow new tower blocks on the right, these are blocks of the Ministry of Justice and there is a sign on the road entering the Campus. Further in, there are good directional signs within the campus to Block H. The office you need is to the left of the main entrance to the Block H tower.
The office has three attendance desks of which two were staffed. Both staff were very sweet when dealing with clients. There were four clients waiting, I was attended within 20 minutes. I spoke to the clerk in bad Portuguese, she scanned my passport, entered details on the VDU and produced an embossed certificate. It cost 5 Euros, paid in cash (I think there was a notice about the multibanco not being accepted) and took 5 minutes at the desk.
I wasn't asked for any other identification but I was asked if I worked in Portugal (which I don't and I have a non-resident NIF) so I don't know where the conversation may have gone had that been a yes (NIF/tax documents etc??).
It was totally painless and fast, it takes around 45 minutes to get there from either the airport or the city (3 stops from the airport), so I would also suggest it might be worthwhile for anyone needing this in a hurry who is coming from the UK or another country with low-cost flights, to fly in and out to do this. Had I come from the UK to do this and booked a week ahead, the round trip would have cost me 49 Euros from London and been do-able in a day.
So I'm just adding a bit more detail to bump it in the hope that the next person who searches finds it in google like I did.
Happy new year all.