Download SD from iTunes to iPad when not purchased thru itunes

How do you download the SD version of a digital copy of a DVD/BluRay/Digital disk pack that has been redeemed in iTunes or movies anywhere etc. I cannot use the movies anywhere app because my ipad doesn't support the latest update and it needs 10 so i need to do this thru iTunes on my Mac. I used to be able to get both HD and SD versions of digital copies from disks before but now i can't figure it out. The HD take up too much space on my small 16 gb iPad. Thanks!