Open Firefox and on the top right of the window click on the options button, then choose “Preferences”. (You can click the images at the right to enlarge them).
In the window you can see a list of all saved passwords in Firefox. Choose the account for which you wish to view the password and click on “Show Passwords”.
A window will pop-up asking you to confirm this command, click on yes. Now you can see the passwords.
The account will be removed, and as you can see in this example, there are no other passwords saved on the browser.