I've done this before , as long as you cut off at least 50mm it's no problem.
1/ Simply cut it off with a hack saw (make sure it's square)
2/ Get a Dremel tool (small finishing barrel style grinder) and ream out the handel off cut from inside the shaft .DON'T GO TOO BIG.
3/ Use the small tool to grind the shaft off the handle.
4/ clean up with some sand paper and glue back in
Takes 10 mins but carbon dust makes a mess in your garage so do it outside , if you don't have a dremel style grinder just buy the tool and stick in the end of a small drill.Keep the heat off that will only wreck your handle and shaft.
You can buy one of the grinders with all the bits for only $29
http://www.mytoolstore.com.au/dremel-cordless-nail-grooming-p-754.html
Rob