migrations/2017_11_26_013050_add_user_role_relationship.php
public function down()
    {
        Schema::table('users', function (Blueprint $table) {
            $table->dropForeign(['role_id']);
        });

        Schema::table('users', function (Blueprint $table) {
            $table->bigInteger('role_id')->change();
        });
    }
public function down()
    {
        Schema::table('users', function (Blueprint $table) {
            $table->dropForeign(['role_id']);
        });

        Schema::table('users', function (Blueprint $table) {
            $table->bigInteger('role_id')->change();
        });
    }
Reverse the migrations.

@return void