Before we begin, we need to go over a few things.

Prerequisites

1. Time and Patience
   Don't start working on this if you're in a rush. Discovering dupes takes a lot of time.
   The initial setup shouldn't take more than 30 minutes, or up to 2 hours if you're completely new to modding.
2. Basic computer knowledge
   While this guide covers a lot, it surely doesn't cover the most miniscule of things like opening files or creating folders on your desktop.
3. A decent computer
   This is mostly just a recommendation, you don't need a top-of-the-line GPU, but some server crashes or lag machines may struggle on very low-end systems. In other words, make sure that you can run the game with at least 30 FPS.
4. At least 4GB of free disk space
   You might not need all of it, but having the space available is strongly recommended.
5. Minecraft itself
   This might come to you as a surprise, but you'll need the game in order to exploit it.