The way I see it you can't
A new portlet can be
An edit properties portlet is none of those.
If you drop the word simple and want to create an alternative edit properties portlet with the tools available to a user you can do that. That is you need to add custom CSS and javascript and a CA PPM version that allows you to use and run those. Then you go with an HTML portlet.
peter.hughes.pemari once gave a presentation on that.