Replacing page/forum main title
I think you mean the navigation/breadcrumb
Go to Templates -> Index
add id="index" to the body tag so it looks like this:
To add something else there you can add whatever you want below the {$header}
Go to Templates -> Index
add id="index" to the body tag so it looks like this:
<body id="index">#index .navigation { display: none;}To add something else there you can add whatever you want below the {$header}