usually by doing it.
Willpower is important, either you take the risk or you don't.
If you cannot get your ass up because you procrastinate maybe the idea is not important enough for you?
So if you're afraid / uncertain:
You will always face obstacles, you will always have a chance to fail life is in constant flux, there are no guarantees.
We as humans are usually more afraid of the unknown not about specific things.
And as soon as you finally muster the willpower and bravery to venture into the unknown and believe in your idea .... we can talk about how to reach your goals.
If you're not willing to move, why talk about directions?