Complex sentence: He won the Icelandic Cup with KR but left at the end of the 1994 Icelandic season to join Hearts, with whom he played the 1994--95 Scottish season.
Split into simpler sentences: He won the Icelandic Cup with KR but left at the end of the 1994 Icelandic season. He joined Hearts with whom he played the 1994--95 Scottish season.