Prop your ladder up against the edge of the roof near to the gutter's end. Ascend the ladder, and align the end of the roll of gutter screen over the edge of the gutter.
Fasten the gutter screen to the edges of the gutter with the gutter clips, one about every 18 inches should be adequate. Continue unrolling, aligning, and fastening the gutter screen onto the gutter, moving the ladder often in order to ensure that you do not have to lean or reach farther than arm's length to unroll or fasten the screen.
Cut the gutter screen at the opposite end of the gutter with the wire cutters. Secure the end with the gutter clips.