Editing an Inspection can only be done when the Inspection is in Draft or has been Denied. If you have the proper permissions (Project Manager or more), you can change the status of an Inspection from the table view or when looking at a single inspection preview.
To edit an Inspection, first locate the Inspection you wish to edit. For help finding Inspections, check out the article - Finding an Inspection.
From the Table
Click the yellow edit button on the far right of the table row;
From the Inspection Preview
Click the blue Edit button on the top right of the page when looking at a single inspection.
Either of these options will take you to the Inspection Basics page. More info about the Basics page can be found here, Inspections - 1. Basics.