Open the project file by clicking the open button. Now you see the entrys on the main pane.
If you have defined a custom text parser you can read the data for it by clicking the parse button. Otherwise skip this paragraph and go to the next section. You will see a dialog. Enter the text that shall be passed to your custom parser class or click "import from pdf" to read the text from a pdf file. Then choose "ok".
Now edit the content fields if necessairy.
Click the modify button. Your files have now been updated.