Step 1: Click Safari on the Apple menu along the top of your Mac’s screen and choose Preferences.
Step 2: Click the Privacy tab and then click the Details button.
Step 3: Press the Remove All button to delete all of your cookies or select the cookies you want to delete and then click the Remove button. Click Done when you’re finished.
Step 1: Click the three-line Menu button in the top-right corner of Firefox and select Preferences to launch the Preferences dialog.
Step 2: Click the Privacy tab.
Step 3: Click the Clear Your Recent History link.
Step 4: Check the Cookies box, click the Time Range to Clear drop-down menu and select how far back you want to delete cookies. Once you've selected your time period, click the Clear Now button to delete all cookies for the selected period of time.
Step 1: Click Chrome on the Apple menu and select Clear Browsing Data.
Step 2: Place a check mark in the Cookies and Other Site and Plug-in Data check box.
Step 3: Click the Obliterate the Following Items From drop-down menu and select the time period for which you want to delete cookies. Choose The Beginning of Time if you want to delete all cookies currently stored by Chrome.
Click the Clear Browsing Data button when you're finished.