Override a class function to include a custom template

Try something like the code below:

function wpse282960_remove_filter() {
    $run_import_some_events = run_import_some_events();
    remove_filter( 'the_content', array($run_import_some_events->cpt, 'some_events_meta_before_content') );
}
add_action( 'template_redirect', 'wpse282960_remove_filter' );