Level 20 is the minimum level for that skill. And if all turtles 20+ already have it, then.. At least you never have to worry about finding a turtle with the skill to train your turtle with?
Oh, maybe I misread your question.
The only way for you to learn how to teach a pet a skill is for you to tame a pet that already has that skill, then have him use it repeatedly.
You will have to tame a turtle with shell shield before you can learn how to teach another turtle how to use it.
Edited, Jan 17th 2008 7:45pm by Ehcks