If you don't know how to do it safely, and the implication is that you don't if you're asking on a music forum, I would recommend not fucking around with 240 volts a.c. In the wrong place, it can ruin your day very effectively. The only sure way to fix thecable is to shorten it as suggested, or replace it. If you're not sure even how to wire the plug up, I would suggest forking out for some professional help. Or a new mower, which may be cheaper! Jim.