Instead of the iso, why not download and install the
deb file from them? Download it, open it up with file-roller, unpack into a directory, then, via the command line in a terminal, go into the directory and enter the command "dpkg -i *.deb" (I'm guessing there will be several deb files to install).
[later edit] Actually, on second thought, perhaps arochester's suggestion (previous post) is best.