Hi All, I know its an old question but its still relevant. I am working with moodle 2.6.1 and the way I have achieved this is as follows.
in file blocks\navigation\renderer.php, in function navigation_node(...) , inside the foreach loop at the beginning after the first if statement;
foreach ($items as $item) {
if (!$item->display && !$item->contains_active_node()) {
continue;
}
// Add this line with the names of the menu items to be removed
if ($item->text == 'My home' || $item->text == 'Site pages' || $item->text == 'Current course') { continue; }
.
.
.
}