Has anybody done this yet? How?

I am attempting to make a custom career called "Convenience Store Clerk". It has three levels, and I decided to base it on the teen retail career. The first level has a career aspiration with one goal. That goal is to reach level 1 of the math skill. Naturally, I will need to create a math skill. For the math skill, I chose to clone the logic skill, since a sim would probably also get a focused moodlet when doing math. So, I come to the two STBL locations - one points to the name of the skill, and one to a description of that skill. Obviously, I don't want my math skill to be called "logic" or its description to be logical, so I chose "Math" as the name, and "It's all about numbers" as the description. I have gone through s4pe and the Data Tool, looking for ways to create a new STBL instance with my new text for my math skill to point to, but there seems to be no way to do this. I hope I am missing something obvious. Any suggestions?