2012 Spyder RT A&C. I'm changing my rear tire myself. Got it off, tire changed and now reinstalling. Go to put the brake housing back and find that the pads are slam shut and have not been able to open them. I have not had this problem when changes the fronts. I know this has been discussed before but I cannot find threads to it. How do I release the piston and open the pads? Need to finish this tonight. Thank you in advance.