Who to use to upgrade/reapair an a&k m60 box mag

[Cain-c-123]

As above. My box mags wiring has decided to poop itself and it's completely dead. Last owner upgraded it apparently. it was running off of a pressure switch and a separate power cable to power it with a 7.4 lipo. Is there anybody who can basically rewire this for me. Or can point me in the direction of how to rewire it myself ? don't fancy paying 85 pounds for a downgrade to the standard M60 box mag.