Each stand was demolished .
Each stand was rebuilt individually in order to minimise disruption , and the new Ruhrstadion officially re-opened with a friendly against SG Wattenscheid 09 on 21st July 1979 .
Each stand was demolished and rebuilt individually in order to minimise disruption , and the new Ruhrstadion officially re-opened with a friendly against SG Wattenscheid 09 on 21st July 1979 .