To edit a scheduled or active review cycle navigate to 'Admin > Review Cycles'. Here you will see all the review cycles created so far.
From here click on the three dots on the top right of the review cycle you'd like to 'edit'.
To edit the review cycle click the option entitled 'edit' as shown above.
Once in 'Edit' mode you can:
You cannot currently change any of the questions or the schedule associated with each step in an active review