Driving last evening, slow speed and had a rear wheel blow out, big hole in the tyre and the tyre left the rim on the inside edge. So, all I needed to do was change the wheel and put the spare on. I could not release the circular disc covering the jack point, snapped a key, chewed up the plastic and no joy. What was I doing wrong? Called the RAC and they did the change for me using a trolly jack.