I have a string:
var s = \'heading
para
\';
and I want to remove the h1 element from it.
Update: I see you just changed the question. Now the solution would be this:
var s = 'heading
para
';
var $s = $(s).not('h1');
$('body').append($s);
Try it out: http://jsfiddle.net/q9crX/19/
Because you now have more than one "top level" element in the jQuery object, you can use .not() (which is basically the opposite of .filter()) to remove the h1.
It would be the same as doing $(s).filter(':not(h1)');
Original answer
$(s).find('h1').remove();
So if you were to append the result to the body, you could do:
var s = 'heading
para
';
var $s = $(s).find('h1').remove().end();
$('body').append($s);
Try it out: http://jsfiddle.net/q9crX/