You can still [URL="http://www.datawatch.com/downloads/Prep.zip"]download Prep[/URL] from the Datawatch support site, but you may want to run the Monarch Utility program, normally installed along with Monarch to see if it will satisfy your prep needs.
Depending upon how your upgrade was done the original Prep.exe program may still be available, especially if you have a stand alone machine rather than a centralised network setup for all applications.
If it is available you can still use it of course.
As Kruncher said the Monarch Utility now includes the sort of fucntionality that was previously available from several individual programs. Also note that, among other things, Monarch's enhanced ability to work with longer lines of data may /Iperhaps have some influence over whether or not you need to run the processes you needed with V6. Obviously existing models may be a factor in that decision.