From a building page, click the pencil icon to open the edit building drawer. Click the Location tab.
From here you can change the address text that is displayed on the building page independently of the map pin location.
You can change the placement of the map pin for the building by:
Dragging the map behind the pin, which also updates the latitude and longitude measurements as you drag, or,
Inputting the exact lat/long measurements in the fields below.
Note: In Google Maps, you can get the latitude and longitude by clicking anywhere on the map to drop a pin, then right clicking on the pin. This displays a menu, and the first item in that menu will be the latitude and longitude (in that order).