How to copy double sided DVD to a one sided disc

I was wondering how to copy a double sided dvd to a one sided DVD9. Thanks

Use DVDFab Merge mode in DVD to DVD. You will need to copy one side of the DVD to a VIDEO_TS folder on your hard drive before you start. Read about using Merge in the Tutorial (the red link in my sig) then post questions if you have any. There is a section about converting flipper discs.