You'll have to go back into your journal either online (app.qeepsake.com) or in the mobile app and find the entry that you want to edit.
The easiest way to search for the entry you want to edit is by searching a word that is found in the question or your response.
How to search for an entry in the mobile app:
Once you find the entry you want to edit click on it and then click on the edit button.
How to search for entry online:
Click the 'Tap to edit' button to edit the entry.