Just buy
one of these. This is the part you sawed in half. Buy a handful; this is a wear item.
Remove the cover by unscrewing the four big Phillips-head machine screws on the bottom. Then pull out a couple of meters of wire, and then freeze the reel in place with strategically placed duct tape. That will prevent the wire from being sucked in.
Then take apart the waist socket,
making sure you notice how the waist socket spring is held into that socket, desolder the wires, untie the knot, remove the spring, remove the screws holding in the old cable guide, pull that guide off, put the new cable guide over the wire (make sure it faces the right direction (##)) ) and put everything back together. You might choose to shorten the wire because the last three inches get the most wear and are probably due to become bad soon anyway.
-dk