In addition to what has been shared with you by Joe 5859 on fraternal correction, I would have to say that the nature of the relationship is also extremely important. For example, I have brothers who I have had to discuss issues with which could be labeled as admonishments to sinners. In each case I was able to discuss the problem with them because we have the kind of relationships where tough conversations can happen without judgment or anger. On the other hand, I have relatives who need to be admonished that I would never be the one to talk to them as I would make the situation worse. If you really want to accomplish something this important it has to be taken on by the right person. I never assume I am the only one who knows what has to be done and if it isn’t right for me I turn it over to prayer.