Changing a non-conforming use.
To a conforming use:
Any non-conforming use may be changed to a use conforming with the regulations of the district; provided that a non-conforming use so changed shall not be changed back.
To another non-conforming use:
A non-conforming use may be changed to an upgraded non-conforming use approved by the board of adjustment; provided, that a non-conforming use changed to an upgraded non-conforming use, shall not be changed back.