Complex sentence: The change in name marked the birth of the Classic Hits Network we know today however the Classic Hits brand was not rolled out to the rest of New Zealand until 1993 and by this time, the wide-ranging playlist had been trimmed down significantly.
Split into simpler sentences: The change in name marked the birth of the Classic Hits Network known today; however, the Classic Hits brand was not rolled out to the rest of New Zealand until 1993. By this time, the wide-ranging playlist had been trimmed down significantly.