Simple answer is i dont know if you can remove it,i had one and couldnt remove it,even the lbs mech couldnt ,seems theyre pressed on.
You could try the headset lower race trick-to tap a screwdriver into the join,working your way around,but this is likely to cause a bit of damage to the spider and the crank.
Why would you want to remove one ? is it damaged?.if your stripping the crank arm prior to polishing, you'd prob' be better leaving it in place and covering it in masking tape
Sorry best i can think of