How do you get the honor blade of chorrol in oblivion

First of all, you have to conplete the 'Seperated at Birth' quest that you start in Chorrol by talking about rumors.

When you have completed this quest (which is pretty quick to do), you need to do the 'Legacy Lost' quest which you get from Guilbert Jemane (one of the lost brothers). This quest is basically killing some ogres around their home.

Approximately two days after completing 'Legacy Lost', you need to be in Chorrol, where Fathis Ules will contact you about the 'Sins of the Father' quest. The quest will lead you to Redguard Valley Cave, and you will probably have to fight through some ogres to reach the Honourblade of Chorrol. From then, you can either not complete the quest and keep the blade for yourself, (I highly recommend this option), return it to Fathis Ules, (you get a leveled amount of gold), or giving it to Chorrol Castle, (where they will give you the Escutcheon of Chorrol; a powerful sheild, but worth less than the Honourblade).

Hope this help =)