How to drill through hardened steel??

How accurate does the hole need to be? If it doesn't need to be super accurate, try finding a shop that has an EDM. It essentially burns a hole through the metal using a vibrating hollow tube that arcs and slowly burns away the metal. The shop I worked at many years ago had one for removing broken taps & drills. Many people thought it was a laser, but it's not.

Electrical discharge machining - Wikipedia, the free encyclopedia