Just wanted to add another successful SAS fix to this thread. Thanks for the write-up and feedback comments everyone. I had a very hard time getting the airbag off, mainly because I was confused at what angle the flat screwdriver should be inserted in the two slits to push the spring. Once I got past that stage though i did the whole thing in like 1 hour
Got up to the stage of where I had to remove the lens with the torx6 and I couldn't find my screwdriver set so I just cleaned the disc (top side only) with alcohol. Note i still managed to remove the optical disc carefully and slide it out of the lens without touching. The dust on the disc was a crystal like dust which i'm not sure how it got there. It did not look like dried grease or anything similar. Maybe its just plastic shavings from something rubbing. Seriously couldn't figure out what it was.
Put it all back together, drove around the block for 2 mins, no more dreaded Christmas lights on my dashboard. I took all the precautionary measures which I read about, (battery disconnected, wheels straight, lights on on re-connection, clean hands, no rubbing of reverse side of disc, turned the wheel full left and full right couple of times after re-connection) and it all went ok.
Not sure how long this repair will last , but saved me from a huge bill from the dealer.
Also note, I accidentally closed the trunk whilst battery was disconnected, but I was able to re-open it with the key inside the key -fob. Not sure why people said here that you need to jump start the car if you do that, maybe i'm missing something.