Complex sentence: In 1967, the council constructed a greyhound track around the outside of the existing football pitch used by F.C. Clacton but it also required the stands to be dismantled and the pitch to be shifted once again.
Split into simpler sentences: In 1967, the council constructed a greyhound track around the outside of the existing football pitch used by F.C. Clacton. This action required the stands to be dismantled and the pitch to be shifted once again.