2008 T5, noticed a small oil leak and traced it coming from the top of the engine on driver side. I suspected based on some forums it could be the camshaft cap and after removing a few in the way items think that is the case [see photo.] I have a replacement but a little prying has got me nowhere and I'm concerned I'm going to severely mar up the aluminum heads before I get it out of there.

Any trick to swapping these out? The cap was cheap and I've got this far.

Thank you for any suggestions.

Rear camshaft cap

 

The leak would be from one of the rear cam seals - the cap just covers the access to the cam seal so any scratches etc would not cause the leak. Check Youtube for vids on replacing the rear cam seals themselves. Note that cam seal leaks can be caused by PCV issues so you should test for positive crankcase pressure. On older cars like the 850s sometimes the seals just need to be pressed back into position.