That's how I would do it.
But do you consider your present substrate "live sand" and what you have to be "live rock"?
If so, a more drastic rinse might be needed, because if, as mentioned above, there were many macro organisms present, and not totally removed by rinsing, they could potentially die in fresh water and create an ammonia spike.
Before adding fish, adding fresh water to the tank, and changing the water periodically every couple days for a few weeks should kill of the animals, and changing water and rinsing could remove them. This might also help cycle the tank, because as they die, ammonia would be released and jump start your new fresh water biological cycle.
Exactly^^