You can mount the first ISO some where. Then copy the files from it. Next move the the ISO number 2 through 4 under the same directory were you copied the files to. When the installer asks for disk 2 through four, you can mount the ISO image on top where it is accessing the first disc. This is without editing some scripts, but you will have to know where the installer mounts the first disc.
Another way is to use four DVD-RW or DVD+RW discs.
BTW, SUSE sucks. Use something better like Ubutu or something else.