AFAIK it can be .....
When you say they have removed the hardware from your 2002, I assume you mean the PSE, Linear Compensator, Antenna Switch, and the phone/cradle/holder. If you have voice recognition, that should work as well.
I have the install bulletins for both MY MLs on a support website. The web address is at:
http://home.earthlink.net/~phdwebsite/
You can download them both and compare the differences yourself. As you will see they use almost all the same pictures and verbage. The only real difference is they don't show the Timeport install. The reason isn't because it won't work. It's because they don't sell the Timeport any longer. The new PSE listed in the 2004 install bulletin does not work with a Timeport phone. You must use the one out of your '02. Let me know if you have any other questions. Please feel free to E-mail me. Remember, you will need to have the D2B network version coded at the dealership if you do the install yourself.
Paul