find a old board with the same pins. cut the solder of the back with a stanley knife ir grind if with a abrasive end on a drill or alike.
Push pin through socket from the back of the board,
go to halfords or alike and buy a rear winscreen metal conductive paint for about £11.00.
Purchase a tiny held held drill bit and holder from a good tool shop.Drill through the socket in the hole of the broken pin , keeping the hand held drill bit as straight as possible, twist slowly and push down at the same time.
the bit will go staight through the board- be pateint it will go through.
get the replacement pin and insert it in the hole just drilled, the piece of staight pin will stick out at the back of board ,even if its a bit short it should be ok.
Get your conductive paint bottle and insert a coctail stick or nail in the bottle, so there is a tiny blob of conductive paint on the tip and using a pair of gasses or magnifying glass dab the tiny piece of pin on the back of the board where the drill hole is, dont try and solder as it will make contact with the other pins.- let it dry for a bit, with a bit of luck this works.-PS check the new pin is in the right place and pointing in right direction in its place in socket.
Yours-martinfox1@ntlworld.com