<?php

$instance_url = "http://{site_url}/rest/v11";
$username = "admin";
$password = "password";

//Login - POST /oauth2/token
$auth_url = $instance_url . "/oauth2/token";

$oauth2_token_arguments = array(
    "grant_type" => "password",
    //client id - default is sugar.
    //It is recommended to create your own in Admin > OAuth Keys
    "client_id" => "sugar",
    "client_secret" => "",
    "username" => $username,
    "password" => $password,
    //platform type - default is base.
    //It is recommend to change the platform to a custom name such as "custom_api" to avoid authentication conflicts.
    "platform" => "custom_api"
);

$auth_request = curl_init($auth_url);
curl_setopt($auth_request, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0);
curl_setopt($auth_request, CURLOPT_HEADER, false);
curl_setopt($auth_request, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($auth_request, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($auth_request, CURLOPT_FOLLOWLOCATION, 0);
curl_setopt($auth_request, CURLOPT_HTTPHEADER, array(
    "Content-Type: application/json"
));

//convert arguments to json
$json_arguments = json_encode($oauth2_token_arguments);
curl_setopt($auth_request, CURLOPT_POSTFIELDS, $json_arguments);

//execute request
$oauth2_token_response = curl_exec($auth_request);

//get token to expire
$oauth2_token_response_obj = json_decode($oauth2_token_response);
$oauth_token = $oauth2_token_response_obj->access_token;

//Unfavorite record - PUT /<module>/:record/unfavorite

$unfavorite_url = $instance_url . "/Accounts/ae8b1783-404a-fcb8-1e1e-56f1cc52cd1a/unfavorite";

$unfavorite_request = curl_init($unfavorite_url);

curl_setopt($unfavorite_request, CURLOPT_CUSTOMREQUEST, "PUT");
curl_setopt($unfavorite_request, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0);
curl_setopt($unfavorite_request, CURLOPT_HEADER, false);
curl_setopt($unfavorite_request, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($unfavorite_request, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($unfavorite_request, CURLOPT_FOLLOWLOCATION, 0);
curl_setopt($unfavorite_request, CURLOPT_HTTPHEADER, array(
    "Content-Type: application/json",
    "oauth-token: {$oauth_token}"
));

//execute request
$unfavorite_response = curl_exec($unfavorite_request);

echo "<pre>";
print_r($unfavorite_response);
echo "</pre>";