letting go

I know I need to let go, but I am so lost as to how to do it. Perhaps you just let go over time, and there is nothing you can DO to speed up that process.

It's easy for me to tell people not to over think things and dwell on stuff in their lives that they cannot change or have no control over. I seem to KNOW this for myself, but have the worst trouble following that advice myself. Isn't that always the way?

So how do I go about doing that?