In a message dated 2/15/2013 8:16:21 P.M. Eastern Standard Time,
stuartmacm@GMAIL.COM writes:

Tap  gently
around them with a rubber mallet and work them off  evenly.

BAD IDEA.
 youll just break all the tabs off.

the only way to remove the centercas from the wheels is to REMOVE THE
WHEELS FROM THE VAN. then you can remove the centercaps from BEHIND by carefully
 pressing the tabs together.

oh..and you have to have the wheels OFF THE VAN to install the front caps
on a 2wd. (grease caps in the way)   otherwise youll break them.

ive broken many centercaps by being lazy and not wanting to remove the
wheels.. :)