Download TextureEnder

Field release of Minecraft 1.6.1 has become a topical issue of the conversion of the old texturepack in resurface. So the game developers created a simple tool called TextureEnder that allows you to accomplish this, it is enough to specify the path to the archive of the texture pack and the program will automatically generate all under the new version of Minecraft

Details on the conversion of the textures in the resources and back, you can read here