There are four prongs that attach to circut board these can be re-soldered if you are very careful and don't let iron get too hot.
F20 pulls apart if you un-skrew 2 skrews on bottom of unit.
I have the wiring what I did which was very fiddly was to solder very thin wires to the connector and onto the PCB then glue back in place. The other option which I'll use next time if it breaks again is to solder a lead with a socket on the end. That way it should never break.