If you know what the names of the handles that the plugins use are, you can locate them using this code and then just use a simple wp_dequeue_script
function.
function wp_inspect_scripts() {
global $wp_scripts;
echo '<pre><h1>Script Handles</h1><ul>';
foreach( $wp_scripts->queue as $handle ) :
echo '<li>' . $handle . '</li>';
endforeach;
echo '</ul></pre>';
}
add_action( 'wp_print_scripts', 'wp_inspect_scripts' );
function wp_inspect_styles() {
global $wp_styles;
echo '<pre><h1>Style Handles</h1><ul>';
foreach( $wp_styles->queue as $handle ) :
echo '<li>' . $handle . '</li>';
endforeach;
echo '</ul></pre>';
}
add_action( 'wp_print_styles', 'wp_inspect_styles' );
Add the above code to your themes functions.php
file for this to work.