I’m not sure there is an editing program available that will decrypt and rip commercial dvds that have copy protection on them. If there is no copy protection on your yoga dvds then there are many different programs that can work for you.
If you need a decryption program, I’d suggest starting with a free one called DVDFab HD Decrypter. DVDFab has changed slightly from the past, nowadays you have to download the entire program to use the free section. You’ll be using up the 30 day trial of the main program as you use the decryption part, but the free section will continue to function after the trial is up. This program will get the video on the hard drive for you to edit.
For editing the dvds, I’d suggest one of two commercial products, either Womble Mpeg Video Wizard DVD or VideoReDo TV Suite. Both can work with dvd video and edit with minimal reencoding at the cut/edit points. There are free trials available for both programs.
If you want a more general purpose editor, that can still work with dvd video, look at Adobe Premiere Elements.