How to Delete Cookies Using the Safari Web Browser:
Steps 01:
· Select "Preferences" from the top Safari menu.
Steps 02:
Click the "Security" tab.Then Select "Show Cookies".
Steps 03:
Select "Remove all". Alternatively if you only wish to delete a select group of cookies, highlight them and select "Remove"
Note:
Read the confirmation message and click "Remove"then Select "Done".
Another procedure for Clear All Browsing History in Safari :
1)Click on Edit and choose Reset Safari…
2)You then get this confirmation screen where you can decide what to keep and what needs to go. Keep in mind that once you hit the Reset button there is no turning back.
*******A quick way to verify it worked is to check the History. Looks like all is clear.
Opera on Mac OS X: