First point of call must be your appointer. Don't sweat it, they have dealt with these before. Let them know what you are planning. Next, you need to talk to the RAF Recruiters and confirm that you will be offered a job. Don't assume that you will slide easily from one to the other (however, I have seen others who have moved right and upwards at the same time!). Once you have both sides of the equation lined up, the appointer will take you through the whole process - they have examples of the letters, etc that you will need to raise to COs and all other interested parties. It's not as daunting as it sounds.
Only word of warning is to bear in mind the JPA transfer that the RN is about to start. Transfers are actually termination in one service and reenlistment in another, and this can cause pay problems.
You will also need to assess your honest promotion prospects, and the chances of staying in the location that you have identified. As we all know, nothing stays the same, and you should be prepared to end up somewhere else (exigencies of the Service, and all that). Your appointer should have a good RAF contact for you to work this out.
Good luck.