I need to copy a shell scrip to the live cd. I don't even care where it goes I just want it on the cd when I boot it. I have tried a few different options. I tried Ubuntu Customization Kit but that didn't seem to give me the option to copy a file. It seems like I am have making this harder then it needs to be. I tired to mount the iso on my Mac but I wouldn't mount. I was going to mount it and copy the script over to the root of the mount point just for testing.

.iso is basically an archive. There are also managers made specifically for them, AcetoneISO for e.g..

Edit.

A live cd/dvd is usually three parts. One is a loader, two is some associate files and three is a compressed image.

I tend to modify the compressed image.

You take that file out of the image to a computer and modify it. As it is compressed you usually have to un-compress it and modify the contents. Then re-compress it back in the same manner it was. In some cases you have to use exact compression level and program level.

If you simply want to add this script to the associated files it may or may not be available to the user but you could copy cd to directory and add script file then create iso again. I've not make a hybrid iso yet but I'd guess common tools would be used like geniso or such.

A "Live CD" uses an iso9660 filesystem which is a read-only filesystem. That means you cannot make any changes to it as is. If you were able to mount the CD and tried to copy anything to it you would get a message similar to the one below:

You would need to mount the CD, copy the mounted iso folders/files to another directory and copy the file there and re-create the iso with mkisofs or genisoimage. Even if you could do that, I doubt it would work the way you want as the directory/file layout on a Live CD is different. Modifying the compressed image suggested above should work but it seems like a lot of effort to get just one script. Why not create a persistent flash drive and use that? If you want it on a CD/DVD you could use mkisofs/genisoimage on the flash drive to create the iso to burn to a CD/DVD.