You can set it using
PlayerControllerClass = YourPlayerController::StaticClass();
DefaultPawnClass = YourPawn::StaticClass();
You should have these available in contructor of your game mode.
You can set it using
PlayerControllerClass = YourPlayerController::StaticClass();
DefaultPawnClass = YourPawn::StaticClass();
You should have these available in contructor of your game mode.