Maintaining enthusiasm is hard if there is no sense of achievement for the first five years. Goals need to be both short and longer term. Scepticism often prevails. But, only if you mean it. But . . .
Most success comes from clarity.
Clarity of purpose, clarity of plan, clarity of communication, clarity of conviction. Finding them may be difficult, but people who feel left out will give you grief later. Find them and involve them and you will increase the commitment of everyone. This will help pre-empt resistance to the change and help you develop clarity of purpose. The former reinforces the change as it happens while the latter maintain focus upon the desired direction.