I am not sure I understand whether you are trying to create or edit a cookie, or merely log in to a site that requires a password and login name. To simply delete or edit cookies use * Firefox Button -> Options -> | Privacy | History <u>remove individual cookies</u> ** the option opens a dialogue, if a site then a cookie is selected the details are shown and are editable ** individual cookies may also be deleted, there is a clickable button for deleting If you need to do more sophisticated work, then because the cookies are now stored in a database, rather tan as individual files, probably using an add-on is the easiest method of manipulating them e.g. : * https://addons.mozilla.org/en-US/firefox/addon/cookies-manager-plus/ If you only need to store login info see *[[how do I make Firefox remember my usernames and passwords?]]