Wurst v6.33 for Minecraft 1.8 is an older version of the client, as the current official releases have moved far beyond the v6.x series. You can typically find archived versions of Wurst on the Wurst Client Download Archive or community-led repositories like the Internet Archive . Installation Steps for Minecraft 1.8
: Open your %appdata%\.minecraft folder. Download Wurst v6.33 MC1.8File: Wurst-Client-v6...
To install this specific version, you generally need to follow the "Old School" installation method: Wurst v6