This rep contains two small categories to NSArray and NSDictionary, that create a copy of the collection in which all dictionaries and arrays are recreated as mutable if immutable, recursively through the collection hierarchy. It includes a sample project that demonstrates how to make a deep mutable copy of the NSUserDefaults dictionary representation.
alfonsotesauro/NSDictionary-and-NSArray-Deep-mutable-copy
NSDictionary + Deep mutable copy
Objective-C