Access task properties and call activities using Camunda Modeler

I was using yiaoqiang to create bpmn flows, but now I am trying to use Camunda Modeler. I need your help to know how can I do the following actions.

  1. How can I access to “Task Properties” instead editing xml?

I am trying to access “implementation” property of “User Task 1” user task using Camunda Modeler:

In Camunda Modeler I can only see the “implementation” property in xml after created in yiaoqiang:

But not in UI:

  1. How can I “Open Called Process” that is in another file instead go to the menu to open the file.

What I am trying to do in Camunda Modeler is when I select the option “Open Called Process” in “Call Activity 1”, it will open another file with a sub flow as you can see below:

  1. How to import another bpmn file to use as sub flow for Call Activity?

Thank you

Duplicate thread: How to access task properties and call activities using Camunda Modeler