I've recently purchased a second-hand phone and my number is different than the one shown. How can I either remove it or change it? I've tried to add a field to it but that doesn't work either.
The "My Number" isn't actually stored on the phone, it is stored on your sim card. Stock android can't edit this data. CyanogenMod can, so can iPhones and BlackBerrys. If you can get your hands on one of these then just pop your sim into it and edit the "My Number" field and Bobs your uncle.