This console command resets your stage in the quest with the specified ID. In other words, this console command puts you at the first stage of the quest so that you can start again.
resetquest [quest id]
| Quest ID | The quest ID of the quest you wish to return to stage 0 of. |
resetquest C03
The Silver Hand has a quest ID of C03. The above command would return you to stage 0 of The Silver Hand.