It depends how far along you are in the process.
If you're mid-application, you can. (See steps below.) If you've already submitted all your personal information and identification documents, you cannot.
Steps to modify an existing application:
1. Click "Profile Information" on the account page.
2. Click the page of the item you want to change.
3. Click the "Edit" button at the bottom of the page and enter the information you wish to correct.
4. Click the "Save" button at the bottom of the page.
Note: you will need to confirm your identity in order to modify your application.