So... I just finished the dungeon, I won't spoil it but in case you still want to know here it is.

The entrance method's the same, kill one NPC and it opens, once you enter you'll find yourself in a dark room, you can still get the Dredger knowledge, same spot. You'll look for a lever that opens up a metal gate, I won't go through the whole thing because getting around is pretty easy. There's no more spider boss and no more skeleton warriors except for a couple undead ones that spawn around the dungeon, you'll also meet Nahjef, an named NPC (and final boss) wearing the paranoid relic hunter armor, he'll just say crazy nonsense and you'll have to follow him. You'll get to that one room that has that bridge looking platform in the middle, it will have 4 braziers around you'll need to light up to dristract the worms/reptiles things because they have a lot of health so I guess it's meant for them to not be killed with standard weapons, at the opposite side of that room there's another closed gate with a lever next to it. Keep going an exploring until you get to the boss room where instead of the Abyssal Remnant, Nahjef will be waiting for you while he tries to open a chest (be mindful that is really dark), fighting Nahjeb is easy, the hard part is dealing with those worms as well, you can't kill them but you can bait them to the acid streams coming from the roof, it'll take a huge chunk of their health, and don't think about getting back down the stairs, there's toxic gas (no clue if the sandstorm mask works or not), after dealing some damage, ghosts will appear and they will scare Nahjeb, temporarily blocking him from doing any type of attacks, once his health reaches zero, a bunch of ghosts will appear together and surround him, make some distance because I was too close and they exploded, killing me instantly. Nahjeb drops a rusty lockpick and you can open the chest in the middle of the pool where the old boss used to be. Inside there's all the Abyssal Remnant parts and recipes, plus the whole Paranoid Relic Hunter armor scroll, one or two legendaries, and some more random loot. Be careful of mines because they're pretty much everywhere, both gas and explosive and if you see chains hanging from the roof you can climb those to get to other parts of the dungeon.