
It all happens inside the Presets Manager (left button on the tab bar at the bottom). Just place your finger on the 3 horizontal lines to the far right of the business (or other preset) you want to move and drag it to the place you want it. Voila!
This is true for all the presets: Businesses (including Charities and Personal Medical), Destinations, Purposes, and Vehicles.
And, in case you didn't know, you can also delete presets, too. Just press the red circle to the left of the item you want to delete and a Delete button will appear. Press Delete, and it's gone! (Be aware: no undo!)