With Internet Explorer opened:

1. Press the keys [Ctrl], [Shift] and [Del]. A Popup-Window opens called "Delete browser history". 
2. Remove all checks except the selection "Temporary Internet files and website files". 
3. Click on the Button "Delete" to empty the browser cache. In comparsion to other browsers there is no option to select the time period. You'll delete all cache data. 

With Chrome opened:

1. Press the keys [Ctrl], [Shift] and [Del].
2. A new window opens called "Clear Browser data". 
3. Here you can select in the upper dropdown-menu, for which time period you want to delete the cache data. You can select between "last hour", "last 24 hours", "last seven days", "last four weeks" or "all time". 
4. If you want to delete all cache, select "all time". 
5. Check the box in front of "Images and Files in Cache". 
6. Submit your selection by clicking the "Clear data" Button.

With Firefox opened:

1. Press following keys at once: [Ctrl], [Shift] and [Del]. A Popup opens called "Clear recent history". 
2. In the dropdown menu, you can define the time range you want to delete the cache. You have the following options: "last hour", "last two hours", "last four hours", "today" or "Everything". 
3. To delete all data, select "Everything" from the dropdown-menu.
4. Make sure the "Cache" checkbox is selected.
5. With a click on the "Ok" button you delete the cache.