Here is the easiest way with out looking for silly medical supplies.
1.Get a threader (hook on one end, point on the other) you can make one from a coat hanger.
2.Tie your leader with your preferred brand and size of treble hook.
3.Thread the leader through the liver so that the leader goea straight through the middle of the liver piece.
4.OPTIONAL*Wrap the piece of liver with miracle thread, done.
(everyone should have a threader and miracle thread.(the elastic kind, not the regular sewing thread type)