Do you have a slow cooker? Easiest way to do the prep, recipe online google frozen oranges marmalade, cook them in slow cooker or saucepan if you must, much easier to scoop out insides and cut up the soft peel. Then you just do the finishing off boiling with sugar in a saucepan. Slightly shorter time obviously if not frozen but I always buy extra and freeze and make fresh batches few times a year.