Click on the three dashes in the top right corner.
Click on settings in the menu.
Scroll down to bottom and Click on Show advanced settings…
Click on Clear browsing data…
Select Cached images and files from the list.
Click on Clear browsing data on the bottom. Your browser cache is now empty.
Usally a “force refresh” is enough. You can achieve this by pressing the following key combination: Shift + Ctrl + F5