Group owner or admin can remove other group owners

app/controllers/users_groups_controller.rb

@@ -19,7 +19,7 @@ class UsersGroupsController < ApplicationController
 
   def destroy
     @users_group = @group.users_groups.find(params[:id])
-    @users_group.destroy unless @users_group.user == @group.owner
+    @users_group.destroy
 
     respond_to do |format|
       format.html { redirect_to members_group_path(@group), notice: 'User was  successfully removed from group.' }

app/views/users_groups/_users_group.html.haml

@@ -10,7 +10,7 @@
   %span.pull-right
     %strong= member.human_access
 
-    - if show_controls && user != @group.owner && user != current_user
+    - if show_controls && can?(current_user, :manage_group, @group) && current_user != user
       = link_to '#', class: "btn-tiny btn js-toggle-button", title: 'Edit access level' do
         %i.icon-edit
       = link_to group_users_group_path(@group, member), confirm: remove_user_from_group_message(@group, user), method: :delete, remote: true, class: "btn-tiny btn btn-remove", title: 'Remove user from group' do
@@ -20,4 +20,4 @@
     = form_for [@group, member], remote: true do |f|
       .alert.prepend-top-20
         = f.select :group_access, options_for_select(UsersGroup.group_access_roles, member.group_access)
-        = f.submit 'Save', class: 'btn btn-save'
+        = f.submit 'Save', class: 'btn btn-save btn-small'