The site footer is defined in a block - a piece of reusable content that can appear on any page. To change the footer you will need to be logged in as an Advanced site editor.
To change it, select Site building > Blocks from the menu, then look down the page to find the BWARS Copyright block in the Footer section. Click the configure link to access the block's configuration page. Simply edit the content in the Block body and click Save block… Read more