Disclosed is a mill liner assembly for a grinding mill. The mill liner assembly including a mill liner and a head nut for the mill liner. The liner comprises a wear surface and an opposite inner surface. The head nut forming part of a coupling for use in removably mounting the mill liner to an interior surface of the grinding mill. The mill liner assembly further comprises at least one passage having an interior wall extending through in the liner for receiving the head nut. The head nut includes a leading end and a trailing end being spaced apart along an axis. The head nut also comprises a body having an interior bore extending along the axis operative to receive a shank, the shank forming part of the coupling, and an engaging portion connected to or integrally formed with the body to engage the interior wall of the passage to retain the head nut in the at least one passage in the mill liner. Also disclosed is a method of installation of a head nut in a mill liner.