Hello, this is Meranda from Angie's List.
Yes, you can update a previously submitted review. It will go through the same approval process as your initial review before being posted. Sign in at www.angieslist.com and go to the Account menu in the top corner. Click on "My Reviews" to view the reviews you've submitted.

Choose the review in question and click Update next to the review to make any changes - once you are finished, click submit to confirm the changes.
Thanks!