I use an air impact tool. Toss the stock axle, get a flush mount.
HERE

 

I've done five sets of lowers and never needed the impact. Take a 6mm bit and put it on the end of an extension with an everyday ratchet.
Trick is, TIGHTEN first then loosen. Comes off everytime. Make sure you loosen these while the fender is still on the bike or else the slider will just spin around and around.

If by chance you do screw up the head somehow (like using an impact or the wrong bit), just drill the HEAD off the the bolt. You have to disassemble the fork anyway. Once you drill the head off, the slider will come right off and you just unscrew the remaining shaft (the bolt) and throw it away. No need to cut the slider in half.

lp

I think this bit set cost like 9.95 at walmart. No need to cutoff allens and such....

 

If you went with chrome lowers...might as well go with chrome wheels, chrome rotors, chrome calipers....with stainless brake lines. I did, one thing led to another!! lol

 

I bought an 3/8 drive extra-long 6MM hex from Snap-On. I used a 1/2" air impact and the bolts popped right out in about one second.

The original 6MM bolts had - what looked like - silicone on the thread surface and that is obviously a factor regarding removal. I applied - sparingly - silicone on the new bolts. By the way, discard the old bolts and install new ones; it says so in the service manual.

 

+2 check my album. On the PCV pipe I think you'll need to split one side to make it slide over the fork tube.

 

One other tip that allways works for me is to use coarse valve grinding compound on the allen tip of the socket with an air impact wrench. I have never striped one yet using this method. The valve grind comp. adds more grip to the allen tip and bolt. Lik was said before most times if you just use a ratchet wrench, you will strip the head. Also when you use the air impact(I use a 3/8 drive) push up on the socket with some fair amount of pressure.