The ICOM IC-706 series comes with a HM-103 microphone with a modular plug as the connector. The disadvantage with these connectors is that the lock pin easily breaks. Replacing the modular plug should be quite easy with a modular crimp tool. However there are some caveats. If you need the schematics of the microphone you find it here (download the instruction manual).
In the old connector you will see two black wires. After cutting the old connector and pealed off the outer skin of the cable you will discover that there is only one black wire. In addition to that, there is a red wire and a gold and silver shield.
Keep the old modular plug to see how the wires should be placed. Trim down the shield leaving just one or two single “straws” from it. The shield should go where the middle black wire is in the old connector (pin nr 5), between the white and the green. The red one is not used and should be cut off.
Getting the wires in the correct positions in the modular connector is a bit like building a ship in a bottle but with patience you will get it in place. Double check the wire colours against the old connector before you crimp it with the modular tool.