pig tail the 2 balcks with each other on the fixture, pigtailing is first twist the stranded wire indivually. then pig tail both with each other, then hold that even with the solid wire from house and twist a wire nut on real tight, wrap with 8 inches black electric tape

do the same with white wires

attach bare ground wire to metal box or to the bare house ground wire with wire nut

just keep the colors with each other

dp. let us know how you do