Hi. I have never changed one, but does the inner cable just have square ends at each end, i.e. could the inner cable go in either way, and where is the cable snapped? if snapped at gearbox end,(sods law says it will always be the speedo end)! then you can pull the inner out, and thread the new one into the outer twisting the inner as you do it, if not employ someone with long arms, and eyes on stalks, who can lie on their back. Hope this may help you. Regards Roger