Matthew 18:15-17 clearly and specifically sets forth the practical steps for confronting and correcting a wayward believer.
First, one believer (usually the offended person) will meet individually with the other believer to point out the offense. If the brother or sister listens and confesses, the matter is resolved.
Second, if the one-on-one meeting is unsuccessful, the offended person will attempt to meet with the believer again, taking with him one or two other members of the church. This allows the confrontation of sin and resulting correction to be confirmed by two or three witnesses.
Third, if the person still refuses to listen and change his behavior, the matter is to be taken before the entire congregation. The whole church body will publicly confront the believer and encourage him to repent.
Lastly, if all attempts to discipline the believer fail to bring change and repentance, the person will be removed from the fellowship of the church.