This is a jQuery plugin for enabling People Picker control on SharePoint 2013 pages.

1. Download the script files and upload it to a location (either in style library) or 15 hive on your SharePoint server
2. Provide a reference to the jQuery library before we use the plugin
3. Provide a reference to the sppeoplepicker.min,js on the page
4. Create a div element with an id attribute
5. call the spPeoplePicker() on the div element in document.ready function

I also uploaded the original JS file. It is open and you can change it as per your requirement.