deleting hidden system files

Does anyone know what software to use to get rid of these SMS templates on
my Nokia phones internal memory and the pre-installed tones and sounds and
gif's that I don't want to free up internal memory? - They are either hidden
or if I can see them they are write only and wont let me delete them I would
have to change the attribute or something. I am using file manager through
Bluetooth at the moment but next week my mini-USB data cable should come
through the post but I don't think it will come with any software though
just a Data cable.
any advice on software would be great thanks - its a series 40 phone by the
way.

Andy.