As the Envelope Sender, if the Recipient has not yet signed or performed the action assigned to that Recipient, they can be removed by using Correct. So if you had 3 Recipients, each having a Signature Tag, and Recipients 1 and 2 Signed, only Recipient 3 could be removed via the Correct feature. Otherwise, you would need to Void and resend. In your example you should be able to Correct and either change the Reviewer Recipient or remove them entirely as long as you are the Envelope Sender.