Anchors are designed to be driven into the soil leaving about 1" - 2" above the ground. Once the anchor is in the ground, insert the signpost into the anchor and secure with a corner bolt and nut. If the sign post is ever damaged the original anchor can be reused.
For anchor installation choose from a manual or powered device and the corresponding drive cap. When using a power driver a shank and appropriate drive cap is required.
For more information on drivers and drive caps see Post Drivers and Drive Caps.