Remove unused js/css references - css

Question

I'm new to web development and am using Laravel. For this, I purchased a HTML admin page template which already included Laravel (so basically Laravel plus the theme in HTML already set up). Now I'm using some elements from everywhere inside the template and I ended up having heavily long reference lists. I don't think this is necessary or even considered good code (rather HTML markup), and I even tried to remove some of the references, but then for some reason some elements of the page do not properly work anymore.
For example, I choose a certain button element from a HTML page included in the template, I copy the code and paste it inside where I need it. I also copy the references, but not necessarily all the references (because there were not only buttons on the page). However, not having -all- the references ended in a messed-up page with few things working. I wonder if there is like any tool which automatically removes these statements since I feel that the following is ridiculous compared to the actual size/content of the page (which is merely a form to enter your personal data):
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrapvalidator/css/bootstrapValidator.min.css')}}"/>
<!--page level styles-->
<link type="text/css" rel="stylesheet" href="{{asset('assets/css/pages/wizards.css')}}"/>
<!--End of page styles-->
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/inputlimiter/css/jquery.inputlimiter.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrap-colorpicker/css/bootstrap-colorpicker.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/jquery-tagsinput/css/jquery.tagsinput.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/daterangepicker/css/daterangepicker.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/datepicker/css/bootstrap-datepicker.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrap-timepicker/css/bootstrap-timepicker.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrap-switch/css/bootstrap-switch.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/jasny-bootstrap/css/jasny-bootstrap.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/datetimepicker/css/DateTimePicker.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/j_timepicker/css/jquery.timepicker.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/clockpicker/css/jquery-clockpicker.css')}}" />
<!-- end of plugin styles -->
<link type="text/css" rel="stylesheet" href="{{asset('assets/css/pages/colorpicker_hack.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrap-switch/css/bootstrap-switch.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/switchery/css/switchery.min.css')}}" />
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/inputlimiter/css/jquery.inputlimiter.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/chosen/css/chosen.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrap-colorpicker/css/bootstrap-colorpicker.min.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/daterangepicker/css/daterangepicker.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/datepicker/css/bootstrap-datepicker.min.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrap-timepicker/css/bootstrap-timepicker.min.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/bootstrap-switch/css/bootstrap-switch.min.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/jasny-bootstrap/css/jasny-bootstrap.min.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/fileinput/css/fileinput.min.css')}}"/>
<link type="text/css" rel="stylesheet" href="{{asset('assets/vendors/multiselect/css/multi-select.css')}}"/>
<!--End of plugin styles-->
<!--Page level styles-->
<link type="text/css" rel="stylesheet" href="{{asset('assets/css/pages/form_elements.css')}}"/>
(Not to forget all the JS at the bottom!)

Answer 1

Just simply go to Google's developer by clicking Short cut (control + shift+ I) and then go to Audit tab, you will find all the details and performance audit report. From there you can find the used and unused css and JavaScript codes.

Answer 2

You can inspect the particular webpage. During inspecting, you can find out the error/unused portion of css/js files in console. They basically name the unused file with line number.