To save a detailed report manually, copy and paste the html-code of each round in the textfield called "HTML-source of detailed (rounds) report" one by one.

To obtain HTML code of a combat report, press right mouse click on the battle report web page and select the appropriate item from the drop-down menu (or use a shortcut key) as suggested below:
if you are using Internet Explorer (IE) select "View Source";
if you are using Opera select "Source" or press CTRL+U;
if you are using Firefox (Mozilla) select "Page Source" or press CTRL+U;
if you are using Chrome select "View page source" or press CTRL+U.
Select the entire text (e.g., by pressing CTRL+A) and copy & paste it to the combat report field. After saving, you will be offered a link to the battle log.