How do I delete cache and cookies?

Deleting your temporary internet files depends on which browser you are using:

For Internet Explorer:  go to "Tools" / "Internet Options/General" / "Temporary Internet files" / "Delete files"
For Firefox: go to the menu icon / Click on "History" / "Clear recent history" / "Details". Select "Cookies" and "Cache" and click on "Clear now"
For Chrome: go to "More tools" / "Clear browing data." Select "Cookies and other site and plug-in data," and "Cached images and files," select "Clear browsing data."
For Safari: go to "Preferences" / "Privacy" / "Details" / "Remove All"

You can also press Ctrl-Shift-Delete (PC), Cmd-Shift-Delete (Mac) in any browser to open the 'Clear Browser Data' window.