Particular embodiments establish static redirection of a function that is a member of a class to an alternate implementation of the function. A software tool executing on a computer server receives an executable file for an application and a location for an alternate implementation of the function. The function may be written in Objective C. The software tool can be used to locate a structure for the function by traversing serialized metadata in the executable file. The software tool can then be used to modify the metadata in the executable file by updating the value of a selector indicating the location of a current implementation of the function to indicate a location of the alternate implementation. The selector may be included in a element of the structure for the class method. Finally, the application may provide the modified executable file for installation on client devices.