Thank you for your replies, I managed to do it by inserting this HTML in the form's metadata label, in the description section
Also I managed to run some JS function by ensuring I had an add event listener to it, I found out by going to one of those JS validation pages, it advised it needs that to fire the JS script, but the below doesn't as it's done via Bootstrap 🙂
<span class="glyphicon glyphicon-info-sign" data-toggle="modal" data-target="#myModal"></span>
<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button>
<h4 class="modal-title" id="myModalLabel">Instructions</h4><br>
<div class="col-sm-12">
<img src="linktoimagehere"
</div>
<div class="col-sm-12"><br><br>
</div>
<hr>
<div class="modal-body">
<p>
Praesent commodo cursus magna, vel scelerisque nisl consectetur et. Vivamus sagittis lacus vel augue laoreet rutrum faucibus dolor auctor se.
</p>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-primary" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div>