Changing Optifine settings with Minecraft closed | Fix options that make you crash

Watch the video:

0:00 - Explanation
1:44 - Locating game files through Twitch
2:04 - Locating game files through Minecraft Launcher
2:17 - Changing Optifine options with Minecraft closed
2:36 - Changing shaderpack with Minecraft closed

Trying to set up a shaderpack, but the game crashes whenever you click a new option? Set something wrong that prevents you from launching the game at all? Well, if Optifine is your issue, this video shows you how to change its settings before even launching Minecraft.