Its all detailed in "My Secret Falklands War" by Sidney Edwards - you can get it from Amazon I think.
He was sent to liaise with the Chilean AF at the start of the war - based in the Embassy in Santiago.
Chapter 6 describes how they decided to use San Felix Island and he went out to check its suitability - problem was still fuel so there was an RAF Hercules sent to Easter Island and repainted into CAF colours to run supplies from the Mainland - even then it was touch and go so they fixed it so the Nimrod could refuel at night at Conception on the mainland and stay on San Felix during the day.
The book is a mine of information on RAF ops in and around Chile - only 100 pages and its not a great work of literature but you can see why it's something no-one wants to talk about for 99 years...............
They bumped him up to Group Captain afterwards & he was given a Civil List OBE with no mention of his "services" in the War - but it was given to him by HMQ herself.