$c1 = 'consumer_key';
$c2 = 'consumer_secret';
$c3 = 'oauth_access_token';
$c4 = 'oauth_access_token_secret';
$tweet = new TwitterOAuth($c1, $c2, $c3, $c4);
$response = $tweet->post('https://api.twitter.com/1.1/favorites/destroy/290993750392578050.json' ) ;
echo "<pre>";
print_r ($response);
echo "<pre>";
for example the tweet “id_str”: “290993750392578050” exists and it was favourited by me years ago but i can’t destroy this favourite.