Remove saved password in Firefox

In Firefox, select the “Menu” button located at the upper-right corner of the window, then choose “Settings
Select “Security” on the left pane:
Scroll down until you see Passwords and select the “Saved Passwords…” button:
Select the web site you wish to remove in the list:
For individual site passwords, select the one you wish to delete, then select “Remove“. To clear everything, You can select “Remove All” to delete all saved passwords. Select “Close” when you’re done.