Complex sentence: Band would spend a year negotiating with Geffen to buy back the album master and then spent the last twelve months creating his own record label, later agreeing a partnership with EMI Records for distribution of the album throughout the world.
Split into simpler sentences: Band would spend a year negotiating with Geffen to buy back the master tapes. Almost three years after recording had been initially finished, he agreeing a partnership deal with EMI Records for distribution of the album throughout the world.