leatherworking warcraft

How can you get 3rd proffesion on World of warcraft?

Hey guys i need help i had Tailor and leatherworking but i need Skinner and this is on my lvl 12 char so can you guys plz tell me how to get 3rd proffesion

That would be nice, but Blizzard only allows 2 main professions. Unlearn tailoring and pick up skinning.