There are two meanings of "Convert Blu-ray to DVD":
1, Maybe you want to convert Blu-ray to DVD with HD video that is playable on a Blu Ray player. If so, you may go to this link:
2, It has another meaning: Convert Blu-ray to DVD with SD video that is playable on any standard dvd players. I hope the tutorial bellow will help you do that.
Step 1, Convert Blu-ray to VOB file using Blu-ray Ripper.
Step 2, Convert VOB file to VIDEO_TS folder using dvdstyler.
Step 3, Burn VIDEO_TS folder to a blank dvd. Burn DVD Video Tutorial
You can suggest me is there any other method to convert blu-ray to dvd or any other questions, please contact me