I own an axia. Don't try to remove it yourself.

I managed to do it, for the same purpose, to replace new one.

I tried multiple things.. screwdrivers, knifes.. ended up able to take out all of them but created scratches on the rim.

Best way is to remove whole wheel.

If you don't want to do that to all your 4 wheels, then just keep the cap in your car, and when you bring for next alignment/balancing.. you can replace at that time.