Since he won't answer, it seems to me like this is what he did. If not...regardless, it should be close enough.
materials: One Ipod (with docking station)
one retro boombox
one set of old, bad, computer speakers. http://www.kalyx.com/store/images/QUAPS160.jpg
those would do quite nice.
1. Pop open the computer speakers. Cut the 2 speaker connections. Remove the board and the transformer (be careful around the transformer primaries - the parts the plug into the wall)
2. Pop open and gut the boom box. All you want left are the speakers.
3. Attach (solder or crimp connect) the wires from the BOARD of the computer speakers to the boombox speakers. Respect polarity (+/+, -/-) if possible.
4. The input to the board should have a plug that can already plug into the ipod! You're good to go!
See, these comptuer speakers ususally have a decent amplifier board, but terrible speakers. And the boombox looks more retro.
Also, if you want, you can run it off batteries! (probably). You need to be at least a little electronically talented to do this part, though. If you wanna know, just ask...