Complex sentence: The band members were all friends of Sigurjón Brink an decided to form the band and perform his entry together as a tribute, in the end they won the national final and will represent the country in the song contest in Germany.
Split into simpler sentences: The band members were all friends of Sigurjón Brink, and decided to form the band and perform his entry together as a tribute. In the end they won the national final and will represent the country in the song contest in Germany.