My comments are as follows:
1. It is much easier soldering in the new wires to tle left transducer if you detach the headband. There's one black screw in the middle holding it - you can't miss it. Then the plastic shell can be pulled out. When soldering keep in mind that you need to thread the cables through this shell!
2. I used dremel to remove the 3-pin connector. First drilled through the plastic core and then cut the metal housing on one side. Then it was easy to take it out with pliers.