How to "inline" a sub-model?

[Michael Heidemann]

I hope I understand now correctly what you like to do:

You have a pedestrian that is in model a that is used in model b. Now you want to "move" the pedestrian to model c that is also referenced in model b and the pedestrian should be at the exact same position.

Hmmm....
If that is correct I do not know about an actual tool that can handle that task.
I have a very vague idea how to solve that, but currently it is too late to give a fully qualified solution.

In the meantime please answer if my idea of your problem is correct.