Complex sentence: It was originally planned that Montreal's new baseball team, the Montreal Expos, would play home games at the Autostade, but the team instead elected to use a renovated Jarry Park, and the new stadium was configured for CFL football use.
Split into simpler sentences: It was originally planned that Montreal's new baseball team, the Montreal Expos, would play home games at the Autostade. Instead, the Expos opted to use Jarry Park, and the new stadium was configured for CFL football use.