The Lore style system makes it very easy to brand your knowledge base to look exactly like your existing web site. Adding your own header and footer is as easy as editing two files.
Go to the /styles/default directory on your installation ("default" may be substituted for whatever style you are using). Open header.tpl. Find the following line:
{include file="html_header.tpl"}
You can either replace html_header.tpl with the filename of an HTML file containing your site header information, or you can delete this line and simply copy and paste the desired HTML in its place.
Repeat the same process for footer.tpl, only substituting your site footer information instead.
Note: If your header or footer files contain PHP code, you will need to use {include_php} instead of {include}, for example:
{include_php file="my_header.php"}