Localization - change current bundle so appropriate xibs are used?

We need to localize our application, and allow the user to choose the language at runtime.

I know how to get translated strings:

var path = NSBundle.MainBundle.PathForResource("en", "lproj");
NSBundle languagebundle = NSBundle.FromPath(path);
string word = languagebundle.LocalizedString(translate, "", "");

but is it possible to select/load the default/current bundle for the running application so that the translated xib files are used?

I can't find anything on the Apple developer docs.