How to switch player controller from FirstPerson to VR pawn (and inverse)?

Hi everybody,
I have a problem that stop me on my project dev, because I have a First Person game but i need the possibility to switch (by click or other) to Vr mode (i use Oculus head display) and inverse too.
I tried

something but without success;

Please HELP!!!

I am in searching of good method to do the same.

Bumping up in hope someone answer this