Complex sentence: The ECB intends to redesign the notes every seven or eight years and a new series, called "the Europa series", is being released gradually, note by note from January 2013, with the first notes having entered circulation on 2 May 2013.
Split into simpler sentences: The ECB intends to redesign the notes every seven or eight years. A new series, called "the Europa series", is being released from January 2013; the first notes entered circulation on 2 May 2013.