How to Install and Activate the Realistic Wolves Resource Pack
Placing the Pack in Your Resource Packs Folder
Once you have the pack file, move it into Minecraft's resourcepacks folder. You can reach this folder from the game itself: open Options, then Resource Packs, then click Open Pack Folder. Drop the pack file directly into the window that opens. Do not unzip it — Minecraft reads the pack as a single archive.
Enabling It In-Game
Return to the Resource Packs screen and look under Available. The pack should appear there. Click its icon so it moves to the Selected column, then click Done. Minecraft will reload its textures, and any wolf you look at should now use the new, more lifelike fur and facial textures.
If the Pack Does Not Show Up
If the pack is missing from the Available list, confirm the file is in the correct folder and that it is a valid pack archive rather than a folder nested inside another folder. Some downloads arrive as a .zip containing a second .zip; in that case, extract the inner file and place that one in the folder. After enabling, if wolves still look vanilla, check that no other wolf-related pack is sitting above it in the Selected list, since higher packs override lower ones.