Abstract: A signpost support sleeve comprises an upwardly open upright socket member having a horizontal footplate across the bottom, and a vertical spike on the underside of the footplate. A special unsetting tool is driven beneath the plate to apply a removing force directly to the sleeve. In the embodiment shown, the socket member has a square recess for a square post having a forwardly extending, cantilever cross arm to which an appropriate sign is fastened. The footplate is generally rectangular. It extends cantileverly forwardly and bears foot-like against the ground to keep the post from leaning forwardly under the weight of the cross arm and sign. The unsetting tool comprises an L-shaped lever having a tooth at one end engageable with one of three underside openings along the rear edge of the footplate. The openings on the underside of the footplate serve the dual function of providing drain openings for the socket member recess and providing a choice of seats for the tooth at the end of the unsetting tool.