Delete cookies in Firefox by accessing your privacy settings and deleting the cookies associated with a specific site or by deleting all the cookies in the recent history. Deleting the cookies for specific sites requires individually checking the sites, whereas deleting all cookies requires changing the time range and selecting the cookies box.Continue Reading
Click the Menu icon and select Options. Next, chose the Privacy panel at the top of the window, and change the "Firefox will" selection box to “Use custom settings for history.”
While in the Privacy panel, select the Show Cookies button located at the bottom left of the window. After the cookies window appears, type the specific site address in the search bar. This displays any cookies that match the search. Check the box next to the specific site and the cookies, clicking Remove Cookie. Click Close after the cookies are deleted.
Delete all cookies by clicking the Remove All Cookies button located on the cookies search bar screen. Alternatively, click the Menu icon, select history and click Clear Recent History. Next, change the "Time range to clear" to Everything, expand the details menu and check the box next to cookies. Click the Clear Now button to delete all cookies.