Click the Chrome menu (the three vertical dots in the top-right corner). In the pull-down menu select More Tools > Clear Browsing Data, which will open a pop-up tab.
In the new window, check the box next to "Cached images and files," as well as "Cookies and other site and plugin data." In the pull-down menu at the top, you can control the time period over which you would like to delete data—everywhere from "the past hour" to "the beginning of time."
Click the "Clear browsing data" button at the bottom of the dialog box.