Board Thread:Questions and Answers/@comment-82.2.29.77-20130312180154/@comment-6077852-20130312205148

When you have the texture pack, start tekkit, from the main menu you should see "Texture packs" open it and press "open texture pack folder" the folder that pops up is where you will have to place the texture packs you want to use. Once you have placed a texture pack in the folder it should show up in the list of texture packs on tekkit.

(Note: Do not unzip/unpack the texture packs, if you do, you wont be able to use them until they have been repackaged).