If you equip the hammer you can ring the gong. Actually, you can ring it no matter what you have equipped.
If you hit the gong and then exit the west door, 3 of the guards will run to the gong room. You can then head north, take out a single guard, then either enter Samuel's lair, or go kill the other 3 guards. If you don't use the gong, you have to fight all 4 at once, not that they are that tough.
