1. Click on the wrench icon on the top right of the screen, then ‘Tools’, and ‘Clear browsing data...’
2. In the drop-down menu, choose ‘the beginning of time’ to be sure you clear all of the cookies, and be sure to uncheck all of the boxes except for ‘Empty the cache’ and ‘Delete cookies and other site and plug-in data’ then click the ‘Clear browsing data’ button.
3. Please remember to close all instances of Chrome completely after you clear the cookies.