A class skill cannot be lower than level 1. You cannot remove a skill if it unlocks another skill. You cannot reduce the level of a skill if it contains the maximum number of skills for that skill level. And by the way, if you only have one skill, the Special Ability (SA) will not appear! Because it requires THREE fully developed skills (excluding the class skill). Develop them first ("Skill Wheel" will help you). You should remove skills that are NOT part of the path to the SA. And only then, to generate the desired skill.

But do you really need it that much?