If you're a parent you influence your child's culture identity without even trying. This most commonly happens by raising the child surrounded by the customs and qualities of it's parents heritage. However, if the child has a different cultural heritage from one or both parents, this culture can be introduced as well. It's usually best to do this from a young age.
I'm not sure what you mean by "influence". Do the parents want their child to identify with a specific culture? It's also possible to raise a child to not identify with any culture. Being raised to adulthood in an extreme antisocial environment from a young age would severely hinder the child's ability to adopt a cultural identity later in life.
Not quite sure what you're asking for, but I hope this helped.