To begin editing a document click on the image thumbnail in The Tax Documents Page. This will open a pop-up window with all the document's data and a medium-size version of the image. There you can edit any of the fields except for the upload date and you can also mark a document as a reimbursable expense.
When you hover over the image and you see a magnifying glass you can click on the image to open an enlarged version of the image. Note that the image opens in a different browser tab, so to go back to your work just switch to the corresponding tab in your browser.
To edit a document simply enter the appropriate data in the corresponding field and click the Save Document Button. Exiting the pop-up window without clicking the Save Button will discard any changes you made.
You can also edit the category of multiple documents at once. View the Mass Assign A Category article for detailed instructions.