Patience is essential. It might take a good year of reconnecting before the family feels like they're through the crisis. None of you are the same people you were before. There's also a big difference between forgiveness and reconciliation. You can forgive, but the other person doesn't have to do anything about it.
Reconciliation means both people reach out.
There are often lingering resentments between a parent and the child or between the child and a sibling, which can prevent reconciliation. You just have to deal with those feelings and keep going to counseling or working with a support group or do what it takes to bring the family together again. Something else I recommend is that parents list their expectations for the returning prodigal. The child should do the same. Both sides need to be honest about what they need and the ways they're willing to negotiate and compromise.