[LUKO]

I don't know if this will help you. If you want to change the location of one of the cube face you must select it in the UV room, then click on the selected face button. This allow you first to isolate it from the rest of the other faces, than to move,scale or rotate it in any direction you want and fit it on a part of the image you have loaded. See images i have uploaded. The vertex are red when unselected and black when selected.