Corsa C20xe conversion help!!

[CorsaMonster]

Right hello im new on this forum but i need help with my corsa which already has a C20xe conversion in it, it was all done b4 i got the car so i dont know what whoever did it has done, but i do know tht the speedo doesnt work and my local garage has told me tht the cable is snapped but i need to find out what is needed to replace/fix it coz they arnt sure, so my question for people is what do i need? The car was originaly a 1.0 breeze if thats any help