And easiest thing to use is one (or two) pieces of a medium density wood (like MDF, no hardwoods but wtf'd use them for this anyway). Cut a slot a slightly bigger width than the head tube, but narrower than the headset cups. Its bes to put foam around the bottom of the slot , and bevel the edges so it doesn't scratch your headset, I used a cloth. Then, just lean on one side and hit the other side at the same time so its one movement (otherwise the board would kick up and hit you or your frame). Worked for me, dunno how you'll go.