You can install OptiFine in a few simple steps, which are laid out for you down below. The instructions below utilize the auto install feature of OptiFine, which does all the work for you. You may also manually install OptiFine if you wish to do so. However, those specific instructions are not outlined below.
1. Head over to the OptiFine website using the buttons above and download the version that matches your Minecraft version.
2. Double-click on the OptiFine installer you downloaded. This will open the installer window.
3. Click "Install" and allow the installer to work its magic, integrating OptiFine into your game version.
4. Open the Minecraft launcher and select the new profile if it's not already selected for you.
5. That's it. Now simply hit "Play" to enjoy your improved Minecraft experience.