The steps for clearing your browser cookies varies depending you the browser you're currently using.
Safari
Remove stored cookies and data:
Click Manage Website Data.
Select one or more websites, then click Remove or Remove All.
Chrome
On your computer, open Chrome.
At the top right, click More Tools.
Click More tools Clear browsing data.
At the top, choose a time range. To delete everything, select All time.
Next to "Cookies and other site data" and "Cached images and files," check the boxes.
Click Clear data.
Firefox
Click the menu button and choose Options.
Select the Privacy & Security panel and go to the Cookies and Site Data section.
Click the Manage Data… button. The Manage Cookies and Site Data dialog will appear.
In the Search websites field, type the name of the site whose cookies you want to remove. Items that match your search will be displayed.
To remove all cookies and storage data for the website, click Remove All Shown.
To remove selected items, select an entry and click Remove Selected.
Click Save Changes.
In the Removing Cookies and Site Data confirmation dialog that opens, click Remove.
Internet Explorer
In Internet Explorer, select the Tools button, point to Safety, and then select Delete browsing history.
Select the Cookies and website data check box, and then select Delete.