Hi,
I did mine today,
(1) Stick a screw driver in the larger tube fitting and put pressure on the fitting to rotate it at the same time put a little upward pressure on the screwdriver.
(2) This should create a small gap under the fitting, I then used a small flat screwdriver in the gap and tapping it with a rubber ballet working my way around the fitting to lift it evenly
(3) Use a larger screwdriver to lever the fitting up working your way around the fitting to lift it evenly until around 5mm proud of the cam cover then I was able to pull the fitting out by hand.
It might be worth wrapping the end of the screwdriver in some sparkies tape to help prevent damage. It took me less than 5 minutes to remove both fittings, just take your time and care and no damage will be done.
Cheers
Cameron