Hi & welcome to the forum.
See the previous post on how to extract the ISO from the RAR file then burn it to CD then install it from the there -
https://www.fiatforum.com/ducato/268013-ducato-2-8td-workshop-manual.html
For your 2004 model download the
Ducato eLearn 2002-2006 Workshop Manual from the Fiat Forum downloads page as in previous above post which will open in a new window & take you to rapidshare , choose the
Free Account & the "I want to wait" button below then wait till the red counter counts down to zero then press download button & wait till the save window appears & save the RAR file to your computer.
Then follow the instructions in the above thread to extract & burn to CD & install on your system etc.
RE; service history for your vehicle, the first thing I would be checking is if & when the Timing Belt has been changed as the 2.8 JTD is an interference engine meaning if the belt breaks - very expensive. If not supplied with the vehicle you can also download the Owners manual from the downloads section
https://www.fiatforum.com/downloads.php?do=file&id=141as well as the CD radio manual
https://www.fiatforum.com/downloads.php?do=file&id=142 both found on the 2nd downloads page.
Fiat uses/recommends Selena Turbo Diesel 15W/40 for the engine oil (although I use Urania Turbo LD 15W/40) & Paraflu 11 for the coolant see previous post on changing coolant -
https://www.fiatforum.com/ducato/270410-draining-water-system.html but any good quality oil or coolant with the same specifications would do.
Cheers
