^Depends on what browser you are using... I'll just hope it isn't IE
Clear Cache
Safari - From the Safari menu, select Empty Cache
When prompted... click Empty to confirm that you want to empty the cache
Firefox - from the Tools menu... select Clear Private Data
Make sure Cache is checked & then click Clear Private Data Now
Cookies
Safari - Open Safari and go to Safari > Preferences
Click Security
Click Show Cookies
Click Remove All
Firefox - Open Firefox and go to Firefox > Preferences
Click Privacy
Click the "Show Cookies" button and then click the Remove All Cookies button