Job 1 - cut the protruding section of axle off the end, flush with the rounded bit.
Job 2 - Cut a slot in the rounded bit using a hacksaw or dremel, so it looks like a screw head.
Job 3 - get a wide bladed screwdriver (wide enough to span the threaded axle part) and grind out a notch in it's centre wide enough so when you insert it in to the slot it misses the axle all together. Stick it in the slot, and unscrew.
You could also use something like this to unscrew it after the slot is cut: http://farm4.static.flickr.com/3496/3297827436_7d8d0da401_b.jpg
Job 1 - cut the protruding section of axle off the end, flush with the rounded bit.
Job 2 - Cut a slot in the rounded bit using a hacksaw or dremel, so it looks like a screw head.
Job 3 - get a wide bladed screwdriver (wide enough to span the threaded axle part) and grind out a notch in it's centre wide enough so when you insert it in to the slot it misses the axle all together. Stick it in the slot, and unscrew.
You could also use something like this to unscrew it after the slot is cut: http://farm4.static.flickr.com/3496/3297827436_7d8d0da401_b.jpg