This command will set the specified stage within the specified quest as either complete or incomplete.
setobjectivecompleted [quest id] [stage id] [0 / 1]
|Quest ID||The ID of the quest you wish to complete or incomplete a specified objective within.|
|Stage ID||The ID of the stage you wish to mark as completed.|
|0 / 1||Specify '1' (without quotes) to set the specified quest stage as completed. Specify '0' (without quotes) to set the specified quest stage as uncompleted.|
SetObjectiveCompleted C01 10 1
Proving Honor has a quest ID of C01. Stage 10 ("Speak to Skjor") is the first stage of this quest. This command would set stage 10 as complete.
SetObjectiveCompleted C01 10 0
This console command affects the same quest/stage as the first command, but sets the stage as incomplete (as 0 is specified).