Complex sentence: Approximately six months before leaving the company he was introduced to a new customer service program and he began to tinker with the program's acronym and within hours, he had begun writing this book in between phone calls and during his lunch hour.
Split into simpler sentences: Approximately six months before leaving the company he was introduced to a new customer service program. He began to tinker with the program's acronym and within hours, he had begun writing this book in between phone calls and during his lunch hour.