You should put some leather oil or leather grease or cream on the upper face of the boots ankle and wear them a lot for riding with a real low heel position. During the breaking time, you can either let the top af the zip open, or use heel raisers. Using glycerine soap every day on the breaking area is also a good idea as this will soften them without hurting the leather.
Mine were like that too,
You can either use oil, or water on your knee area while you ride, you can wear them a lot, if that doesn't work, you can always use heel raisers! :)
Use some oil to soften them, and ride with your heels really far down while there is still oil on it