If your right eye causes you to stumble, gouge it out and throw it away. It is better for you to lose one part of your body than for your whole body to be thrown into hell.
Working in the mental health field, I am familiar with several stories of people who have taken this command literally and removed body parts in an effort to reduce sin. Working in the criminal justice field, I can vouch that their efforts to avoid sin were unsuccessful.
Sin starts in the heart and cannot be prevented by lopping off appendages. So what is Christ saying?
This statement is certainly in keeping with Jesus' theme that the impact this life has on the next life is far more significant than the experiences of this life alone. Losing an eye is no loss if it brings spiritual gain.
In truth, to avoid hell, the disciple of Christ may ultimately forfeit more than just body parts, but rather see his whole person crucified with Christ.