In book 1 of Homer's Odyssey, Athena gives Telemachus some good, solid advice about how he is to behave now that he is a man, and this includes killing the suitors if they fail to obey him so that he might claim his authority and inheritance. Let's look at this in more depth.
Athena visits Telemachus in disguise, knowing that there are more than a hundred suitors nearly eating Penelope and Telemachus out of house and home. These men want to marry Penelope, but she will not take any of them, because she has no proof that Odysseus is dead. Yet they refuse to leave, and Telemachus has not been able to take authority over them. They look upon him as merely a boy.
So, as Mentes (an old friend of Odysseus), Athena tells Telemachus what he must do. First, he must call the Achaean heroes together in an assembly and explain the situation. Then, with their backing, he must order the suitors to leave. If Penelope is set on marrying again, she should return to her father's house and leave Odysseus's estate to Telemachus, for it belongs to him and not to the suitors.
Next, Telemachus must go on a journey to assess the situation and see what news he can get of his father. If he hears that Odysseus is alive or likely alive, he should wait another year and see what happens. If he hears that Odysseus is dead for sure, he must perform the funeral rites, get his mother to marry one of the suitors, and then kill all the rest one way or another. If he does not kill them, they will not leave. They will never taken him seriously. Rather, they will continue to impose upon the estate and rob Telemachus of it completely. If he is to assert his manhood and claim his inheritance, he must kill the suitors and step into Odysseus's place.