Gimana cara insert data many-to-many?

gan mau nanya nih cara nya mau insert data ke table skali input lngsung banyak gtu gmn ya? contoh nya kyk assign beberapa murid dlm 1 kelas gtu

ni controller store nya

 public function saveAssign(Request $request,$classId)
    {
      $input = $request->all();
      $messages = array(
        'studentClassId.required' => 'Student class ID required.',
        'scClassId.required' => 'Class required.',
        'scStudentId.required' => 'Student required.',
      );
      $rules = array(
        'studentClassId' => 'required|min:16|max:50',
        'scClassId' => 'required|min:16|max:50',
        'scStudentId' => 'required|min:16|max:50',
      );

      $validator = Validator::make($input,$rules,$messages);

      if($validator->fails())
      {
        #Return to the same page with error message
        return Redirect::back()->withErrors($validator)->withInput();

        #If succeed
      }

      $studentClass = new StudentClass();
      $studentClass->studentClassId = $input['studentClassId'];
      $studentClass->scClassId = $input['scClassId'];
      $studentClass->scStudentId = $input['scStudentId'];

      if(!$studentClass->save())
        App::abort(500);

      return Redirect::action('Classroom\ClassroomController@view_participant',$classId)->with('successMessage','Students have successfully assigned.');
    }

ini Model nya si classroom

 <?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Classroom extends Model
{
    protected $table = 'classes';
    public $incrementing = false;
    public $timestamps = false;
    protected $primaryKey = 'classId';
    protected $fillable = array('classTeacherId','classTrackId','classNumber','className','classStatus');

    public function Student()
    {
      return $this->belongsToMany('App\Student','student_classes','scClassId','scStudentId');
    }

    public function Teacher()
    {
      return $this->hasOne('App\Teacher','foreign_key','teacherId');
    }

    public function Track()
    {
      return $this->hasOne('App\Track','foreign_key','trackId');
    }
}

ini model nya si student

 <?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Student extends Model
{
    protected $table = 'students';
    public $incrementing = false;
    public $timestamps = true;
    protected $primaryKey = 'studentId';
    protected $fillable = array('studentId','studentPic','studentNIS','studentName','studentGender','studentReligion','studentPoB','studentDoB','studentNationality','studentAddress','studentPhone1','studentStatus');
    //protected $dates = 'studentDoB';

    public function Class()
    {
      return $this->belongsToMany('App\Classroom','student_classes','scStudentId','scClassId');
    }
}

mohon bantuannya ya gan hehe