First create an xpath selector function.

function _x(STR_XPATH) {
    var xresult = document.evaluate(STR_XPATH, document, null, XPathResult.ANY_TYPE, null);
    var xnodes = [];
    var xres;
    while (xres = xresult.iterateNext()) {
        xnodes.push(xres);
    }

    return xnodes;
}

To use the xpath selector with jquery, you can do like this:

$(_x('/html/.//div[@id="text"]')).attr('id', 'modified-text');

This works great!!