I noticed the same mistake in their instructions. There is no rubber block on Pinto's but there is in the Mustang, they must have just copied the Mustang instructions. You need to drill out the rivets that hold the regulator to the door frame. That should allow the window to drop enough, if not then you will need to remove the window from the regulator by drilling out those rivets. You can reinstall with small "stove bolts" and nuts or the stock body shop style rivets.