03Firebolt9R...I'm not sure if you're doing this exactly the way I did or not so I'll clarify a bit...
1) You want to loosen the axle JUST until it starts to bind a bit (not too much so that you start to bend the forks or compromise the fork seals).
2) Give the brake side of the forks a swift "smack" with the rubber mallet.
3) If it only loosens a bit, repeat steps 1 & 2 until it breaks free. Those threads are pretty beefy. I personally doubt that you would be able to strip them by hitting the fork with a Rubber mallet???? Just make sure you have a few threads engaged when you do so.
4) If it's still stuck beyond where the threads engage, you'll need to use something small to lightly tap the axle out (I've used a 3/8" socket extension for this in the past). Be careful not to damage anything if you have to perform this step.
Oh....and "penetrating lube" can be your best friend!!(That's what she said):) Just be careful not to get it on your brakes or tire for obvious reasons
I hope this helps you...Good luck!!