One thing I do to loosen up the membrane to make it easier to pull off is the following. I put the rack lengthwise in front of with the long bone end closest to me and bone side down. I then roll the rack in on itself keeping it as tight as possible. Then flip the rack over and usually only a paper towel to pull the membrane off with.
Keep in mind that on the back of the ribs, there is almost a two layer membrane. In other words, there is a thin layer of membrane left on the rack after you pull off the outside membrane. The outside membrane is the one that turns into leather when cooked.
Hope this helps.