The price of a new RX because they'll try their best to sell you a new one...

1) Measure
2) strip couple mm of the rx wire where it needs to be soldered.
3) tin both end of the wires (make sure the iron is hot, hold it down on the wire where you striped it. apply the solder to the wire, not the iron. the wire will just suck in the solder).
4) after tinning both sides, lay them on top of each other and apply the iron tip. The solder on the wires should melt and voila, you just re-soldered your wire.
5) measure and heat shrink
6) RANGE CHECK!!!

You can do it.