Vue2 how to use $refs to target an element and remove css class

I want to remove the css class of an element when a method is called.
but I want to do this using $refs.

template:

  <div class="modal"  ref="myModal"></div>

method:

      closeDropdown: function() {
            this.$refs.myModal.$el.removeClass("open");
      }

>Solution :

this.$refs.myModal.classList.remove("open");