Complex sentence: Three years later the club was permitted to extend the existing small stand on the opposite side and in 1951 Dover F.C. moved to the upper pitch on a permanent basis, initially paying the council rent of £300 a year.
Split into simpler sentences: Three years later the club was able to extend the existing small stand on the opposite side. The club moved to the upper pitch on a permanent basis in 1951, initially paying the council rent of £300 a year.