Replacing Wheel Center Caps

[rubberduckie]

Hey! I bought a great used Boxster last month and now that it has gotten too snowy to take it out, I have decided to fix it up a little bit while I'm waiting. When I got the car I noticed that the plastic crests in the center of the wheels were foggy and I was wondering if it was possible to replace just the crest without replacing the whole wheel. I found something called "colored crest wheel center caps" on ebay and they look like they just pop on, but I can't tell if what I have on my car will pop off. I would hate to spend a hundred bucks then not even have the things fit. Anyway, if i end up getting these, how would you go about getting the old ones off? Thanks for the help!