Changeing Tradeskills spec'sFollow

Only way to change would be to drop tailoring, and relevel it from 1. You will lose all of your patterns, which may be trouble if you had any rare patterns. Once you get to 350 again, I think you talk to the specialty tailors in lower city, though I am not sure. Specialization is meant to be permanent, or in this case just really hard to change. Some other tradeskills were given the option of an easy change with the expansion, because their specializations were fundamentally changed, but since nothing has changed with the tailoring options, it is generous for blizzard to give you even the option I mentioned above.