Complex sentence: Until July 2015, Rijeka played their home games at Stadion Kantrida, which will be demolished before the end of 2015, and is set to be replaced by a new state of the art stadium, scheduled for completion in 2017.
Split into simpler sentences: Until July 2015, Rijeka played their home games at Stadion Kantrida, which will be demolished before the end of 2015. It is set to be replaced by a new state of the art stadium, scheduled for completion in 2017.