A headrest is supported by a first rod and a second rod, the first rod being equipped with a series of positioning notches on a first side and a retaining notch on a second side. In operation, the two rods are installed into two channels in the seat, one of the channels being equipped with a headrest guide assembly. The headrest guide assembly includes a button that allows the user to selectively engage the series of positioning notches on the first side of the first rod so that the headrest can be positioned as desired. However, the headrest guide assembly will automatically engage the retaining notch on the second side and thus prevent the headrest from being removed from the seat. To remove the headrest, a tool can be inserted into a notch in the button and to insertion of the tool prevents the headrest guide assembly from engaging the retaining notch on the second side and thus the headrest can be removed.