On all bikes I've worked on, just be slow and patient, and gently work them out going around with the thinnest thing ya got. You don't want to pry the things off just my cranking on one side only. I use my pocket knife/leatherman personally.

lots of experience here!
Start with the thinnest blade you can find and "gently" raise one side, then remove the blade and replace it with a like thickness piece of metal or plastiic. A feeler gauge works well. With that side supported repeat the process on the other side. As you increase the thickness of your blade and your spacers, you will walk the cap up and out of the hole. It takes a little longer but it has been a long time since I broke one.