To remove a response to a review, you will need to send a request to the review site. The request can take a few hours to be removed, so make sure you always double check that your review is correct before posting.
First, log into your account, and click on the "Reputation Management" tool. Then click on the "EZ Response" Option in the menu. Next, click the "Review/Response Feed" button.
Next, click the "Request Response Change" button as shown below.
Finally, just input what you'd like done (remove response, edit response to:, etc.). Click send, and your response change will be submitted.