Ever needed to buy some Adept or Expert level spells but didn't want to join the College of Winterhold for roleplaying reasons? Or perhaps you didn't mind joining the College but you didn't want to have an unfinished questline stuck in your quest log? Maybe you have no interest in magic at all but just wanted to sell that Elder Scroll or those Unknown Books to Urag? If you've ever been in one of those two situations, then this video, made by CarlosBenDer21413419 on YouTube, is for you. Basically, it shows you how to enter the College of Winterhold without starting the questline by using the exit from the Midden Dark and then working your way up through the Midden.
While the above is my preferred method, it's worth noting that you can also use the Wooden Plate Glitch to pass through the gate or Klimmek's Sack Glitch to get over the walls. Unfortunately, there are a few limitations of using methods such as these to enter the College. First is that since you never start First Lessons, Faralda will continue guarding the bridge. Second is that since fast travelling to the College of Winterhold places you outside the gate, you can't use fast travel to get into the College once you've discovered it. In other words, you have to glitch your way in every time you want to go there, so I recommend doing this only whenever you need to get in there to buy a spell. Finally, you won't be able to do any of the side quests such as the ritual spell quests. Still, entering the College of Winterhold this way has its advantages for characters who don't want to join it.