"I am an SGI member. How can I attain Buddhahood."

The Lotus Sutra teaches,

"By what means can a person attain emancipation, 

Separating oneself from falsehood and delusion. " - Lotus Sutra Chapter 3, A Parable of the Burning House

Separating oneself from the Soka Gakkai is to separate oneself from falsehood and delusion and of course continuing to chant Namu myoho renge kyo.

Namu Myoho renge kyo

Namu Myoho renge kyo

Namu Myoho renge kyo