Hello Oscar, You are right to be confused by this sentence. First thing that makes it hard to understand is the presence of two pronouns for which antecedents must be found: "them" and "their". Do these refer to the same people? Clearly not, but it's better not to force the listener to struggle with such matters. The second problem is similar. The passive phrase "if said the proper way" also needs an antecedent. If WHAT is said the proper way? Again, the listener can figure out this puzzle if he struggles with it, but why force a listener to do this? A third problem I see with the sentence is that a "point of view" is not something that can be "said". A point of view can be expressed, stated, presented, revealed, told, understood, or promoted, but it can not be "said". There are exceptions but, in general, you only "say" words. To fix it, one could write: "If parents present their point of view in a winning way, they can persuade their children."

In the context of this reading, parents are not forcing their children to see their point of view, instead they are gently trying to change their child's mind through setting an example.