Depends if the edge of the crown race is "exposed" at all…for example on my RS forks they have the indents so you can get to the edge of the crown race; you can then turn the fork upside down, get a friend to hold the forks then use a nail punch with a hammer alternating sides after each strike.
Where its not exposed, I've found you can use a chisel very carefully putting the flat side of the blade against the crown then the sloping side against the crown race. Again, rotating the fork after each strike.
As daffy says, use a bit of penetrating lube first and also a bit of insulating tape of exposed bits of the fork will prevent some potential marks.