Well, I bought a Prodigy Express unit today, but have yet to buy the decoder upgrades for my locomotives. For four of my Locos, it will be a simple board replacement: Kato SD-40-2, C44-9W, P42DC, and SD70Mac... I'll begin acquiring those shortly. However, for three of my Locomotives, which are Life Like Canada GP9 "Chop Noses" the decoder installation is a bit more involved. Since these units will be the switching backbone of my layout, I definitely want these locos to be DCC equipped. I understand from one source that the frames will need milling in order to receive a wired decoder... both Lenz and Digitrax Z-Scale decoders are certainly small enough. Has anyone done this type of installation before? I have a Dremel unit and a hacksaw, but wondering what sort of bits I would need and precautions I would need to take in order to properly install the decoders on each of these little gems.