Files on a CR-RW can be modified on the CD, on mine anyway. The
RW stands for Read/Write. If it has a Read Only Attribute, just
remove it.
....
Off-topic hardware discussion.
There are a few ways to write CD-RW disks. One is ISO format, in which the
CD-RW disk is indistinguishable from a CD-ROM at the logical/content level.
In that format, all files on the disk are read-only, and the disk can't be
written. It can be REFORMATTED and REBURNED, but it's not read-write media.
CD-RW disks may also be formatted as, IIRC, UDF. CD-RW disks with that
format are read-write media.
All CD-ROM, CD-Read/Write and DVD/CD drives can read the former. Not all of
them can handle the latter, either reading or writing. Your comments would
only apply to the latter, but it's highly unlikely that's the OP's
situation.