twinfan is right, thats the prefered solution.
but as its 2 conductor wire, if you need to do this fast, you can do a DIY job and even keep the screening all the way down the wire.
buy some 2 conductor wire from wdmusic, or something like that.
you can pull back the screening of the wire pretty easily with that braided stuff. do that, and trim the end of the wire so the screening overlaps the end of the wire when its pulled back. do this to the end of the wire attched to the pickup, and the new piece. solder the center conductor and insulate, then pull the screens together and solder those.