Alquima Labs is very commonly know as labs, or the Skill Book instance. Labs is the instance on the Asmodian Side that drops their level 42 skill books. In order to gain access to Alquima you will need to complete the "A Missing Father" Campaign quest. This quest is quite a pain in the ass but it gives you access to this instance which chances are you will need to do.
After you've completed the Missing Father Quest getting to Alquima Labs can be quite an accomplishment in its own. In order to get here you will need to run northeast from Chaos Brambles. Take a look at my map below to get an idea.
The whole path that you will follow is littered with elites. Chances are you will agro something while running up here, the good news is usually you can out run them. You'll need to be good at dodging mobs or get good to get up here safely. Below is a video of the usual path to take in order to get up here.
Once you're here and inside you'll be in the very commonly farmed "first room". Many groups clear the first room and reset the instance for the sole purpose of farming for Skill Books. The main reason that groups clear the first room is because it is easy. The drop rates are pretty crappy in the first room but the mobs can easily be plowed through quite a few times.
Right when you enter you will see the door in front of you to go to the next area. In order to get the key to open this door you will need to kill the elite NPC in the room northwest of you. His name is Researcher Zoiks and he will drop the Daevic Genesis Lab Key that you need to open the door. Once you're through this door you will need to kill your way up the hallway and into the right room.
Here you will need to kill Key Protector Nimue for the Lepharist Sanctuary Key. After you've gotten this you will want to clear the room across the hall, the Daevic Gensis Lab. This is a pretty dangerous room since the Biologist mobs in here can literally one shot you. It may take a bit to clear it but there is a quest NPC in here and also the other bit of the instance.
Inside this room you will find Strahein. You can turn in a quest to him, if you have it and also accept a new one called "[Group] Reviving Strahein". This quest requires you to head into the room across the hall with the Key Protector that you killed. In here you will want to open up the Research Cabinet and bring the Antidote back to him. Turn in your quest and accept the follow up.
In this room you will also find the Research Center Power Generator which when you destroy it your quest will be updated and you will need to run outside and set off a flare. The flare can be set off anywhere outside, you can find it in your inventory.
There is a secret door to the north in this room that the Lepharist Sanctuary Key will open. Here you will find a large "throne room" type area. At the very back end of the room you will find High Priest Esras. You will need to kill her in order to complete your "[Group] A Mysterious Book" quest.
After you kill the NPC you will want to return to Beluslan Fortress and turn in both of your quests. That about fully covers this instance. Good luck and have fun!