Most Wurst versions for 1.12.2 use a standalone installer. Open the downloaded file and follow the prompts to create a new profile in your launcher.
Ensure you have run this version at least once in your Minecraft Launcher. Download Wurst v6.35 MC1.12 OF
If your version did not come with OptiFine bundled, download the 1.12.2 version of OptiFine and place it in the .minecraft/libraries or mods folder created by Wurst. Safety Warning Most Wurst versions for 1
Includes built-in support for OptiFine (OF), which can be added manually to the mods folder or is sometimes bundled in the installer depending on the specific "OF" edition. Installation Steps Download Wurst v6.35 MC1.12 OF