The following are steps I have found very helpful in developing a positive and healing relationship when working with families in crisis, either as a placement professional or as a coach.

Find Their Pain: Ask questions of the parent in reference to what it has been like for them and other family members to have a child/young adult out of control. Because it is a family system problem, all members have been affected and deserve attention. The parents will usually admit that their child has been in control of the family.

Give Them Strokes: Parents are probably worn out emotionally and financially because of their child's "at risk" behaviors that may include drug and alcohol abuse, defiance, school failure, social problems or mental health issues. Take the stand with parents that they have done all they know how to do to solve the problems and are now contacting you for solutions.

Ask the Question: After listening for a time and you should determine how long that would be, ask the question "Is what you are doing working?" And then "Are you WILLING to do what I recommend?" This will be the deciding factor if they are committed to do something different or if they are stuck and don't really want help. This may be the time to say that you may not be the right person for them and refer them to someone else.

Get a Commitment: After confirmation of "yes they are willing" to take your coaching and they do want help, then you can move along to do what needs to be done. And that may include a variety of interventions such as an intervention, a placement to a specialty program or school or family therapy.
Provide Direction: Be direct and provide clear instructions to parents as they would not be calling you if they could themselves. Working from a model of loving detachment with an addictive child may be required.

Ask Permission: If you need to bring to light some of the parents' codependent behaviors that may be hindering success, let them know upfront that what you are about to say may make them angry or feel uncomfortable and ask PERMISSION to proceed. I have found this step takes away any fear that I may have and sets a tone of COMPASSION. It provides a safe way to confront behaviors that need to be highlighted in order to start the process of doing something different.