Hacking into a mainframe might look easy in the movies. You couldn't be further from the truth however. You need to fool the admins with the help of proxies. Prolong the trace by connecting through obscure servers in China and Russia. You need an empty apartment with nothing but a rusty stool, a lamp and a $4500 notebook connected to the Interweb. Remember to leave the notebook in the empty apartment when you leave in haste as the police knock on the door. Then it's up to you. Good luck.
-tek