As it turned out I didn't have to. After a bit of digging it seems my original loom should be left in place I just need to remove the USB bit from the new loom and just install that in addition to the old loom.
Guess I should have researched this a bit more carefully. Workmates are extracting the urine as I type!
I'll sort it this weekend! If I do need an auto electrician I'll call these Ceaser chaps. The number has gone in my mobile.