There are few ways. I’ll only cover one here.
Step one: Forget to care about yourself until now. Think something along the lines of “I only have one life to live so fuck it” and not realize that “fucking it” doesn’t mean you’ll live an indulgent, joy-filled, if not entirely hedonistic life, and then one day suddenly die. It means you’ll get sicker and sicker without realizing it, until you’re miserable and need to be hospitalized.
Step two: Have few, if any, remaining meaningful relationships. Either have no one visit you, or have your estranged ex visit and get into a fight with them.
Step three: Be afraid of death.
Step four: Die. But you’re in the hospital so jokes on you, we broke your ribs and pumped you full of drugs and connected a machine to your body, so I guess technically, according to the state, you’re alive. Congrats.
Step five: Die again. And again. And again. The good news here is we’ve likely already broken every rib we can so you won’t have any new broken bones. We will pump you full of more drugs. Until someone – your doctor—looks around the room while everyone is pumping on your chest, waiting for the next timer that tells us to give you more drugs, staring at the monitor showing us your heart isn’t doing live-supporting things and says “does anyone have any other ideas?” And when we’ve gone through the list of possible problems and possible fixes and we still don’t find a pulse then, then you can die.