WordPress change wp_nav_menu walker with a custom one

In general you’d add child substitutions for the relevant templates if possible, as Tom mentions in the comments.

Alternately, you can use a wp_nav_menu_args filter hook to swap in your own arguments prior to WordPress retrieving and rendering the menu:

add_filter( 'wp_get_nav_menu_args', 'wpse406010_primary_nav_menu_args' );

function wpse406010_primary_nav_menu_args( $args ) {
  if( $args[ 'theme_location' ] !== 'primary' || $args[ 'walker' ] !== '\Neve\Views\Nav_Walker' )
    return $args;

  $args[ 'container' ]  = false;
  $args[ 'menu_class' ] = 'primary-menu-ul nav-ul';
  $args[ 'walker' ]     = new Aria_Walker_Nav_Menu();
  $args[ 'items_wrap' ] = '<ul id="%1$s" class="%2$s">%3$s</ul>';

  return $args;
}