files to use with https://github.com/chronossc/django-cbv-utils/blob/4d992533925e4bc2e215cbfa8e98d07853d65784/cbv_utils/views.py#L152

ajax_form.html

{% spaceless %}
{# this is included in form.html and is loaded via ajax #}
{% load bootstrap_toolkit %}
{% if success %}
{# msg in form instead in next request #}
<div class="alert success alert-success">
    <a class="close" data-dismiss="alert">×</a>
    {{ success|safe }}
</div>
{% endif %}
{{ form|as_bootstrap }}
{% endspaceless %}

form.html

<!-- this is original form in html page -->
<form method="POST" action="{% url "your_update_form_url" pk=object.pk %}" class="form" id="myform">
    <div class="form_fields">
        {% with form=user_form %}
        {% include "user_ajax_form.html" %}
        {% endwith %}
    </div>
    <div class="form_buttons">
        <button class="btn btn-primary" name="update" type="submit">Update</button>
        <button class="btn btn-danger" name="reset">Reset</button>
    </div>
</form>

update.js

(function($) {
    // untested code, I changed variables names from working code
    // this js post form via ajax and update .form_fields with rendered form in ajax_form.html
    var $form = $("#myform");
    $form.submit(function(e) {
        e.preventDefault();
        e.stopPropagation();
        var $that = $(this);
        $.post($that.attr('action'), $that.serializeArray(), function(data, status) {
            $that.find(".form_fields").html(data.form);
        });
        return false;
    });
})(jQuery);