Necessary: Patch your game with the MCPatcher. If you don’t, you will get display bugs using these 64×64 textures.
If you don’t like having to patch, vote here.
1) Download the texture pack
2) Launch Minecraft, click Mods and Texture Packs > Open texture pack folder
3) Move the zipped texture pack *as is* (don’t unzip) into the /texturepack/ folder.
4) Download the MCPatcher and launch it
5) Click Patch
6) Run Minecraft and select the texture pack in Mods and Texture Packs
7) If you run into issues/crashes, please head to the MCPatcher thread, read the detailed instructions there and if it doesn’t help, ask for support in the thread. If you are unable to solve the issue, just delete the texture pack.
8) Don’t forget that you’ll have to patch again for each version of Minecraft. (With an updated MCPatcher)