title: How to install paypal merchant SDK
body: <p>I would like to use Merchant PayPal SDK for processing my transactions. On the <a href="https://github.com/paypal/merchant-sdk-php" rel="nofollow">following</a> page there is a brief installation about installing the SDK. </p>
  
  <p>On the GITHUB there are two types of available installation, using <code>install.php</code> and using <code>composer</code>. I prefer installation using <code>install.php</code>.</p>
  
  <p>When I download project from github, there are two folders: </p>
  
  <pre><code>lib
  samples
  </code></pre>
  
  <p>Which folder is important, and which folder should I import in my application and how?</p>
  
  <p>On the GITHUB installation procedure is following: </p>
  
  <p><strong>1.</strong> Create a composer.json file with the following contents:</p>
  
  <pre><code> {
          "name": "me/shopping-cart-app",
          "require": {
              "paypal/merchant-sdk-php":"v2.*"
          }
      }
  </code></pre>
  
  <p><strong>Question:</strong> Where should I put this composer file, how to run <code>composer update</code> etc... Is this step required if I use <em><code>install.php</code></em>?</p>
  
  <p><strong>2.</strong> Install the SDK as a dependency using composer or the install.php script - <em>I prefer second installation using install.php on my webserver? When I run install.php, what will happen?</em></p>
  
  <p><strong>3.</strong> Require <code>vendor/autoload.php</code> OR <code>PPBootStrap.php</code> in your application depending on whether you used composer or the custom installer. - <em>I should use require_once("PPBootStrap.php") if I use install.php.</em></p>