I think to start out you can ask yourself "Why did I hurt myself? How did I help myself? What was it that made things better enough to stop hurting myself?" Once you can answer those questions in detail with out flinching at the answers then you will be in a position to help your friends. I don't have enough information to give you any more advice. I do know that people who cut or hurt themselves have a lot of pain locked up inside and don't know how to get it out in a constructive way. The problem is the pain they are dealing with rather then the SI. If it wasn't for the pain there would be no SI. So I guess rather then trying to make them stop hurting themselves try helping them to stop hurting.
Carrie

<font color=green>Not knowing when the dawn will come, I open every door.--Emily Dickenson