Complex sentence: The two brothers began learning and mastering their instruments, and then approached Shay Av Køden to assume lead guitar duties, having been friends for years and sharing a passion in Heavy Metal, the three then began writing songs and looking for a vocalist and bassist.
Split into simpler sentences: The two brothers approached Shay Av Køden to assume lead guitar duties, having been friends for years and sharing a passion in Heavy Metal. The trio then began writing songs and looking for a vocalist and bassist.