File access after the project has been packaged

Currently I access my custom binary files in the project using the IFileManager::Get().CreateFileReader(*(FPaths::GameDir() + FileName)); function. After packaging the project (with File->Package project) all the assets and other content files are assembled into a single .pak file, so the above function no longer works. How do I go about accessing my data inside this pak file?

Not sure if this is directly related but I’ve been learning how to build and use pak files today and put what I’ve got so far in here: How should we implement in app purchases? - UE4 AnswerHub