There are very reliable butcher stores that sell raw liver. The label typically says, “Liver must be broiled,” which many people have interpreted as meaning that they can broil the liver as they would broil any other meat that was soaked and salted before sale. This is absolutely incorrect. One must be well acquainted with all pertinent halachos and the practical application of these halachos in order to properly kasher raw liver.
On many occasions, I have asked customers if they learned hands-on how to properly kasher raw liver. Almost no one that I asked over the last 20-odd years answered with a firm YES. Please, if you didn’t properly learn how to do it from someone, buy the ready-broiled liver.
Mrs. Levitz, Brooklyn