Its actually easy to do I believe on any model. Essentially once you unwind the belt all the way you will see that there is a spindle. the belt goes through the middle of the spindle and has a loop with a plastic rod in it. what this does is keep the belt from being pulled from the spindle. so you can stick a screw driver in there( worked for me) or anthing to keep it from retracting. once you have done that you just push the belt instead of pull and you will be able to pull the little rod out of the loop in the belt. from there you can just pull the belt out since there is nothing to stop it. it sounds complicated but once you see it you will be like " well no **************** that was easy" if you have the new belts already sewn you just put on the old hardware (anchor buckle etc) and feed the new belt where the old one came replace the rod remove your stopper (screwdriver) and let it wind back up.
ill be doing this in a few days and ill do a step by step.
one thing that will make it easy for me is i have a free set of belts so I can prep all the hardware and belt fabric so when I go to put it in my car i wont even have to remove the spindle (best case scenario) and if its a little cramped ill pull it out and do it real quick and put it back in.