[Plugin: Gallery to Slideshow] How to use this plugin in my theme?

Hello!

I own a WordPress theme (ClassiPress), but I do not like the way the picture shows, opening a popup window.
View demo:
https://demos.appthemes.com/?theme=classipress&doing_wp_cron=1324910582

I know where are the codes, but do not know how to call your plugin to make the display of images attached to each post.

The code currently used is this:

<?php if ( get_option( 'cp_ad_images' ) == 'yes' ) : ?>

                                    <div class="bigleft">

                                        <div id="main-pic">

                                            <?php cp_get_image_url(); ?>

                                            <div class="clr"></div>

                                        </div>

                                        <div id="thumbs-pic">

                                            <?php cp_get_image_url_single( $post->ID, 'thumbnail', $post->post_title, -1 ); ?>

                                            <div class="clr"></div>

                                        </div>

What should I change to use your plugin?

https://www.ads-software.com/extend/plugins/gallery-to-slideshow/