To edit an existing opportunity, make sure the "Opportunities" tab is selected, select the opportunity that you wish to edit by clicking the check box in front of it, then click the "Edit" button in the column of buttons on the left side of your screen. You may also right-click on the profile you wish to edit, and select the "Edit" option that appears. The Opportunity Profile should look familiar. It is the same set of screens that you use to enter new opportunities. You may change any of the information. If you select text you can type over it. You can uncheck previously checked boxes by clicking on them again. You can navigate through these screens using the "Next" and "Prev" buttons or you can click on select specific tabs if you would like a more direct approach.