Complex sentence: In 1925 the club signed Dixie Dean from Tranmere Rovers who, in 1927--28, set the record for top-flight league goals in a single season with 60 goals in 39 league games, a record that still stands.
Split into simpler sentences: In 1925 the club signed Dixie Dean from Tranmere Rovers. In 1927--28, Dean set the record for top-flight league goals in a single season with 60 goals in 39 league games, which is a record that still stands.