For smaller projects like this I use an A-frame I built a few years ago to mark contour. Then follow the line with a walk behind tiller to loosen the soil. Once loose, you can easily use a square shovel to “pump and dump” the soil on the downhill berm. You can get pretty accurate this way. Anything longer than 100-200ft is recommend a tractor or skid steer. Unless you have a few other people to help.