Complex sentence: Chargers owner Dean Spanos tried for 15 years to get San Diego to build a new stadium to replace the aging Qualcomm Stadium, warning that he would move the team to Los Angeles if one was not built.
Split into simpler sentences: Chargers owner Dean Spanos tried for 15 years to get San Diego to build a new stadium to replace the aging Qualcomm Stadium. He warned that he would move the team to Los Angeles if one was not built.