Appliance Repair Questions? Ask a Technician for Answers ASAP
Hello Im sorry you have been waiting for a reply.
It is certainly safe to take the back off of the radio when it is not connected to the mains and replace the aerial. The only precaution I would take is not to touch any capacitors as they may still be holding a charge and could give a shock to you. But I am sure that the aerial replacement is quite an easy task.
I hope that you are able to complete your task.