These days, when things go south while in a fighter, pilots are trained to reach for the loops that trigger their ejection seats. You just give it a yank and the ejection seat takes it from there, launching you from the stricken plane and setting you up for a safe(ish) landing on the ground (hopefully far from people you've just bombed or strafed).
Easy as pie — but it's still something you don't wanna do.
But in World War II, the process was very different. Today's ejection seats use technology that didn't exist in that era, so much of the process had to be handled manually, which was extremely hazardous.
The pilot of a MiG-15 uses an ejection seat to make his escape from a plane that has been shot down.
When future president George H. W. Bush's Grumman TBF Avenger was hit by enemy over Chichijima, the other two men on board were immediately killed and he had to bail out. In the chaos, Bush ejected improperly and collided with the plane's tail — luckily, his injuries were minor compared to what could've happened. He drifted to the ocean below tethered to a parachute and was eventually rescued.
The method of properly ejecting from a World War II-era fighter varied depending on the plane. What worked for a P-38 Lightning wouldn't work for a F4U Corsair. But, in general, the procedure was to slow the plane down as much as possible and manually open up the canopy. That's when things got real tricky.
This gun-camera footage shows a Nazi pilot trying to bail from a FW190.
A pilot's natural instinct is to use their foot to jump from the side of the cockpit, but that would expose him or her to the slipstream — and that means a collision with the tail. Instead, pilots must use their hands on the side of the cockpit and roll over the "wall." Then, the pilot waits to clear the plane (usually with a ten count) before pulling the ripcord, deploying a parachute.