Complex sentence: For the moment, WRKS is simulcasting ESPN Radio's current flagship, WEPN 1050 AM; this September, WEPN will become the flagship station of ESPN Deportes Radio.
Split into simpler sentences: For the moment, WRKS is currently simulcasting WEPN, ESPN Radio's current affiliate at 1050 AM. Once the move of the format to WRKS is finalized, WEPN will become an affiliate of ESPN Deportes Radio.