Bootstrap modal: close current, open new

Without seeing specific code, it's difficult to give you a precise answer. However, from the Bootstrap docs, you can hide the modal like this:

$('#myModal').modal('hide')

Then, show another modal once it's hidden:

$('#myModal').on('hidden.bs.modal', function () {
  // Load up a new modal...
  $('#myModalNew').modal('show')
})

You're going to have to find a way to push the URL to the new modal window, but I'd assume that'd be trivial. Without seeing the code it's hard to give an example of that.

I know this is a late answer, but it might be useful. Here's a proper and clean way to get this done, as @karima's mentioned above. You can actually fire two functions at once; trigger and dismiss the modal.

HTML Markup;

<!-- Button trigger modal -->
<ANY data-toggle="modal" data-target="TARGET">...</ANY>

<div class="modal fade" id="SELECTOR" tabindex="-1">
  <div class="modal-dialog">
   <div class="modal-content">
    <div class="modal-body"> ... </div>
     <div class="modal-footer">           <!-- ↓ -->  <!--      ↓      -->
      <ANY data-toggle="modal" data-target="TARGET-2" data-dismiss="modal">...</ANY>
     </div>
   </div>
  </div>
</div>

Demo

It's not exactly the response but it's useful when you want to close the current modal and open a new modal.

In the html in the same button, you can ask to close the current modal with data-dismiss and open a new modal directly with data-target:

<button class="btn btn-success" 
data-toggle="modal" 
data-target="#modalRegistration" 
data-dismiss="modal">Register</button>