How do you bail out of a helicopter?

Unfortunately, at least during the Vietnam War generation, airmen had to "ride em out", there was no way of bailing out of a chopper. On the other side of the coin (on the other hand), at least the vast majority of downed helicopters were travelling low and slow so that at least when they impacted the ground it wasn't like crashing in a hi-speed jet, consequently there was a descent chance of surviving a chopper crash.