If we really want to change anything, we need to start by itself, before it is an example to others, or bring the knowledge and experience to convey to others properly.
If we want to change something, we have to start from ourselves to be first to be an example to others or the knowledge and experience to pass on to others correctly.
If we want to change anything, we must start from yourself before you as an example to others or to apply their knowledge and experience to pass even if others correctly.