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WinRAR, extract the files from the ISO file, and burn some to each disc.
Or, if you truly need to recombine the original ISO in that format, use WinRAR to compress the file.
Set the compression method to "Store," and set the Split to Volumes to "700m - CD-700M," and also check "Create SFX Archive," which will make it a self extracting archive. It'll splice up the ISO file into separate WinRAR archive files, each just right for a 700MB CD. Burn them, transport them to whatever location they need to get to, put the first CD in, and run the EXE file. It'll splice together the source files into the original ISO file.
Otherwise, if they all need to be on one disc, get a DVD burner.