delete

//views
<div class="post-wrap">
<h2 class="text-center">  <%= @post.title %>  </h2>
    <%= link_to "Удалить тред", root_path, method: :delete %>
<p class="reply"><%= @post.body %></p>
</div>


//contrller
    def destroy
      @post = Theme.find(params[:id])
      @post.destroy

      redirect_to root_path
    end


//routes
  resources :themes