If a review has been created using the wrong form, you can update it as an admin. However, you will first need to make sure there haven't already been any comments added by the reviewee, the reviewers, or any feedback-givers. If you change the form being used after comments have been added, the comments will be hidden.
Go to the Administration Centre > Reviews and find the review you'd like to edit. Click Edit on the righthand side. Under Responses on the pop-up, you will be able to see if there have been comments already added to the review. If there are responses, proceed to A below. If there are no responses, proceed to B below.
Since there have already been comments added, you cannot update the form being used for this review. You can either let the review carry on being completed using the form it was created with or you can close it and create a new review with the correct form.
Note: if you accidentally edit the form being used and the comments disappear, they haven't been deleted and can be brought back by changing the form back to the original one.
Since the review hasn't been started yet, you can update the form being used for this review. While on the edit pop-up, change the Form field to the correct one and click Save changes.