How to make an installer for Android? [To avoid large download]

I think the question is clear from the title,

1. I have an Android program
2. It needs to read some data from a given path, say SDCARD/myAppData/data which is a large file
3. I think, I should allow users to download this large file while installing the App. OR, Say, they can download the file on PC, and then put 开发者_开发知识库it in SDCARD, and then the app will read from the SDCARD. (To save bandwidth for the mobile)

I want to provide user a chance to choose a path for SDCARD or system memory..then the installer should install the data into the chosen path... and work.. normally.

Any idea? Please explain...

About number '2'... It READS or it WRITES data?

Anyway, what I'd do is displaying a "choose your path" screen depending on a flag (it can be on a SharedPreference or SQLite). The flag will be turned on by default, and will only turn off once the path has been chosen (only then you'll follow the "real" application flow).

This is the closest to an installer I can think about on Android.