First, talk to your "brother", speak, reason and dialogue with him. Settle it between the both of you. If in the end, you and him reason things out, then it is solved!
Second, if step one fails, bring along another person or two, to settle it with him/her. Speak it out, dialogue and reason once more. Hear another person's point-of-view; what more get a person who's wiser and you know has dealt with a problem similar to what you to have.
Third, if approach number two fails, bring it to the community. Community meaning the bigger picture - bring him to court if it comes to that, or round up the groups and circle involved. Sort things out, discuss, and once again dialogue.
Finally if all else fails, "treat him like a pagan or a tax collector." As harsh as it may sound, this means that the problem with this person is beyond help. So what to do if it reaches here? Simple, do like what Jesus did, forgive them (see Luke 18:13), make sure to reason with them and most of all let them know what they are doing is not correct - be sure to justify why, and above all pray for them.
The practical guide provided by Jesus can easily be related to; when dealing with a person, it is always wise to reason out on what and why the person did what he did. It's best that problems between people can be solved through understanding, at the smallest point is to always solve it before it gets too large. Furthermore, the four approaches is not necessarily a procedural approach, it can also depend on the gravity of the wrong doing. The most important approach is always to keep in mind to do it with gentleness and respect (1 Peter 3:15).
"Jesus said, ‘If your brother does something wrong, go and have it out with him alone, between your two selves. If he listens to you, you have won back your brother. If he does not listen, take one or two others along with you: the evidence of two or three witnesses is required to sustain any charge. But if he refuses to listen to these, report it to the community; and if he refuses to listen to the community, treat him like a pagan or a tax collector." - Matthew 15:18-17