Once you have wave 2, the first thing you need to do is enable the setting on the sales tab of System Settings.
Once this option is set, the quick create form of the Opportunity Close entity will be shown to users instead of the dialog. You can configure this quick create form like any other form in the CDS.
Keep in mind that if you are using a model-driven app (and if you are using unified interface, you are), you need to add the opportunity close entity and the quick create form to your model-driven app. Otherwise you will still see the old dialog.