Complex sentence: Kilodavis first self-published the book in 2009 via KD Talent of Seattle, then on 21 December of the following year, Simon & Schuster published a new edition on their Aladdin imprint.
Split into simpler sentences: Kilodavis first self-published the book in 2009 via KD Talent of Seattle. On 21 December of the following year, Simon & Schuster published a new edition on their Aladdin imprint.