Tonearm lead connection on last leg

When one lead gets "flappy" the wire has broken and is being held in place by the shrink tubing.  You don't need to redo all four.  Use a razor to slice open the shrink.

Last Lemming you can get new clips on line from several vendors. Buy a set of four that comes with the colored heat shrink tubing to identify the lead. Clip all the old clips off and trim the wire. Do one at a time so you do not forget which color you are working on. You will need a 25 watt soldering iron with a fine tip and electronics solder. You tin the end of each wire by holding the iron and solder against the wire until it melts in.
Insert the wire into the new clip hold the soldering iron at the junction of wire and clip and melt the solder in. Capillary action will suck it right up.
Slip the right color heat shrink tubing on and shrink it with a heat gun, A hair drier will not work. A torch in close proximity will but you have to be very careful not to burn anything. For what you would pay someone to do this you can get all this stuff and more then you will have it around the next time something goes south.

Mike

I would totally try and fix it myself before shipping it off, even shipping just the arm. But you will want proper strippers for that gauge wire. A new clip would be nice, but you could probably re-use the current one if you're careful. You'll need fine tools- although really the parts are soft enough you could probably get by with some quality tweezers. Mostly what you will want is a flexible vise or clamp to hold the wire while crimping the clip. I'm assuming it crimps, as opposed to being soldered on.

Most likely it failed because when removing the clips to change cartridges someone wasn't careful, the clip pulled off and yanked the wire putting a lot of stress where the wire crimps to the clip. Either that or they did a poor job stripping the wire leaving the wire nicked. Either way you want to be real careful not to repeat that mistake because there's just not a lot of wire there to be doing it over again. Lose even 1cm and you could be looking at a total phono lead replacement. So good luck!