Complex sentence: Slash was replaced by Nine Inch Nails touring guitarist Robin Finck in January 1997, who signed a two-year contract with the band in August 1997, making him an official member.
Split into simpler sentences: Slash was replaced by Nine Inch Nails touring guitarist Robin Finck in January 1997. He signed a two-year contract with the band in August 1997, making him an official member.