Modify Value of Parameters of Request
The replace method replaces all of the parameters in the request, so you probably do not want to do that.
I would use the set method instead - So you can do:
$request->request->set('tactill_customerbundle_customertype', $newValue)You can read more in the Symfony2 documentation (http://api.symfony.com/2.0/) - you are looking for Symfony\Component\HttpFoundation\Request (which is the $request variable), which then returns a Symfony\Component\HttpFoundation\ParameterBag when you call the request() method.