Offline Defrag of Exchange Server 2003 database

Can anyone give me simple step by step instructions on how to defrag the files offline? I read many articles but had problems with bad commands at the command prompt. I finally did get it to go from 0-100% but it only took about a minute then said I should do a back up which I did not know how to do. I read that this process should take quite a long time so that is why I think I missed an additional command or something. Please put this is simple non tech instructions.
Thanks much!