You can relocate the buildings inside your base for 500 gold by following these steps: 
-Click on the Command Center.
-Choose "Details" and then "Move Building."
-All buildings will be surrounded by a blue border.
-Choose the building you want to move, and a pop-up will appear with the message: Choose a location to move or swap the building.
-Choose the location you want to move the building to or swap it with another building.

 
Important notes:
-Buildings outside the base wall can only be moved and swapped with buildings outside the base wall.
-Buildings inside the base wall can only be moved and swapped with buildings inside the base wall.