I'd probably just take a dremel with a cutoff wheel and slowly cut through the strands.

A hacksaw might work(?), but seems like it might tend to stick a lot.

after that is done, then go watch the Lock Picking Lawyer and see how he attacks all sorts of locks. Weirdly entertaining. Plus, he does attack a variety of bike locks, so it's interesting to find out which ones are most resistant to attack.
It shouldn't surprise anyone that cable locks are among the least resistant to attack.

Steve in Peoria