The PDF that makerbot sends with instructions to help you install your cable looks like this:
Those bracket areas are not me paraphrasing out the pictures. That's what the document says. Makerbot: quick to market, slow to document.The HBP cable is the thick one coming out of the hole in the bottom plate on the other side of the Zmotor from the MightyBoard, and it's connected to the MightyBoard in two places.[Photo: Cable emerging from hole on underside of The Replicator.] or [Photo: Underside of The Replicator, HBP cable highlighted somehow.] and/or [Photo: Closeup of front half of MightyBoard, all HBP wires highlighted somehow.]The small HBP connector is plugged into the HBP Therm port, right by the ribbon cable from the LCD interface. Disconnect it.[Photo: Hand disconnecting HBP cable from BP Therm port.]
Honestly, tho, it's not that difficult. Just need to be willing to flip the bot over.
Flip the bot up and remove the one screw holding the electronics cover, then remove the electronics cover. As always don't lose that little square nut, it's not glued in there. Unless you've glued yours in there. I should glue mine in there.
That's it. Take it apart, put it back together with the new cable, and I'm back to printing ABS. Easy. Which is good because I've got a ton of chess sets to finish and some other store items to restock.