It can be done!
The best way to do it, IMHO, is to make an ISO image of the DVD using DVD-Decrypter. Now rar/zip this into a spanned archive (just 'store', don't use compression unless you have a few hours to kill!). Now store this split/spanned archive onto 2 DVD-Rs or multiple CDs. (You have to span the archive since it's 7.5GB in size, and thus won't fit on one DVD-R.)
To install the game, un-rar/-zip the file from the DVD-Rs to your harddisk and then use Daemon Tools to mount it as a virtual drive. Install from this virtual drive using the normal game install routine and selecting 'full installation'. Once done, unmount the image from Daemon Tools and delete it to free up space. Now apply the 'No-DVD' patch, and you can play direct from harddisk.
(Installation of the game requires 15GB of initial harddisk space, but once you remove the image the game only takes 7.5GB).
NB. Not posting the 'No-DVD' patch here since aren't sure whether it's against the T&Cs. However, you could try a look around www.fileforums.com
P.S. Forgot to say that your harddisk MUST be formatted as NTFS format (e.g. Windows 2000 or XP), otherwise you won't be able to store a single file over 4GB.