How to reprogram name ident on Panasonic fax machine?

Panasonic fax machine KX-FP181 still has Ident from old name. Using keypad to enter my name does not delete old long name and end of it still reappears, tagged on. Keypad does not have option for blank space to use to overwrite. Moving cursor along does just that and nothing else. Backing up cursor - ditto. Have used an underscore to separate my first and second name but can't delete past that. Going through set-up does not give option to just delete and start again, either. Help !