Oh yeah I see. The only things I can remember from his messages was something about the LED bulb or the area it fits in the boombox had to be sanded or drilled out a little bit. I would say you will need to splice into the existing woofer bulb wires and test your new LED bulbs to be sure they light up properly. I don't know if your new LEDs will be +/- specific, so check that before you mount them and close the radio up.
He also noted this: "I have extra sets with resistors in line already." I'm sure you need something similar.