How to remove the existing file dropzone?

I have this sample:

link

CODE HTML:

<div class="dropzone dz-clickable" id="myDrop">
     <div class="dz-default dz-message" data-dz-message="">
          <span>Upload or drag patient photo here</span>
     </div>
</div>

CODE JS:

 Dropzone.autoDiscover = false;
 var myDropzone = new Dropzone("div#myDrop", {
   addRemoveLinks: true,
   url: "#",
   maxFiles: 1,
   init: function() {

     this.on("maxfilesexceeded", function(file) {
       alert("You are not allowed to chose more than 1 file!");
       this.removeFile(file);

     });

     this.on("addedfile", function(file) {
       myDropzone.options.removefile.call(myDropzone, mockFile);
       //  I want to delete an existing element
     });

   }
 });

 var fileName = $('#profilePicture').val();
 var mockFile = {
   name: fileName,
   size: 12345
 };
 myDropzone.options.addedfile.call(myDropzone, mockFile);
 myDropzone.options.thumbnail.call(myDropzone, mockFile, "https://lh3.googleusercontent.com/-eubcS91wUNg/AAAAAAAAAAI/AAAAAAAAAL0/iE1Hduvbbqc/photo.jpg?sz=104");

What I want to do is when the user uploads a file, then the existing one to be removed.

How can you do this correctly?

Thanks in advance!