Seoul (CNN) -- Kim Byong-soo steps out of his shoes and into his coffin. He slowly lies down and closes his eyes. It is minus 11 degrees Celsius in these South Korean woods, but Kim doesn't seem to feel it. His hands and feet are tied. Only then does he open his eyes as the lid is closed and hammered down.

This "death" is Kim's last chance to regain his will to live.

For 15 years, this highly successful Seoul-based dentist has wanted to kill himself. "Every day I want to turn a gun on myself," he says. "Every moment I'm awake. I think about suicide daily but I can't do it because I have too many responsibilities."

Kim enrolled in the Beautiful Life seminar with the hope it will change his mind. It's a radical technique to help people forge a fresh outlook on life and its founder Kim Giho says that only by dying can some people find their desire to live.

"We can't understand death simply by talking about it. People truly experience death by participating in it and being reborn with a pure state of mind." Kim Giho tries to demystify death by talking about it directly with the group.

As part of his treatment, the dentist has to write a suicide letter, his final words to his wife and children. Writing by candle-light, Kim scribbles furiously.

Earlier he said of his wife: "She knows that I'm having a hard time, but she doesn't know that I want to kill myself and I don't ask her for help. If I do, it will be too hard for her."

Kim is then dressed in traditional burial clothes -- loose fitting hemp cloth -- and taken out into the snow. Along with five others in the group, he is led by a man dressed in black, symbolizing death.

In a small badly lit clearing in a wooded area of Seoul, six coffins have been laid out. Kim kneels next to his, lowers his head and listens as a final prayer is given. This is his funeral.

Then, in silence, he steps into the wooden coffin and lies down. Kim Byong-soo stays in the coffin, seeing and hearing nothing, for 20 minutes.

Kim Giho says this sense of being 'buried alive' can reboot a suicidal mind. He tells me some people re-emerge into the fresh air with tears streaming down their faces, promising a determination to live every day to the full.

When Kim rises from his coffin, there are no tears and he says nothing.

Once back inside the seminar room he re-reads his suicide letter intently. He adds to his letter to his wife and children and tells the group: "Starting tomorrow, I don't want to be that person who just used to eat and work to get by. I want to love others, know how to forgive others and have hope."

Talking about his wife, he says: "Whatever you want I will do it for you."

Just hours after saying that he wants to die, Kim is making plans to take his wife on a holiday.