Dig a trench 6 inches deep along the outside edge of the fence. Pile the dirt removed beside of the trench and discard the turf excavated from the trench.
Unroll the hardware cloth next to the trench. Place the points of the end of the wire into the ground and unroll from under the roll of fencing. Bend the curve of the wire so it lays flat on the ground.
Stand the hardware cloth up in the trench. Press the wire against the fence and attach the two with zip ties. Wrap a zip tie around the hardware cloth and the existing fence, slide the pointed end of the tie into the retaining end, pull the pointed end to tighten the bond. Place zip ties every 24 inches up an down and along the length of the fence.
Cut the hardware cloth with the wire cutters as needed to adjust the length. Snip off the excess sections of the zip ties with your wire cutters. Refill the trench with the original dirt from the excavation. Walk on the trench to compact the soil.