Complex sentence: The album was downloaded over a million times within six days of release, and became the most-downloaded legal torrent of 2014; by February 2015, it had been downloaded over 4.5 million times.
Split into simpler sentences: The album was downloaded over a million times within six days of release, and became the most-downloaded legal torrent of 2014. By February 2015, it had been downloaded over 4.5 million times.