Once inside the hotel, head left. Head up until you hear a warning of grubs. Wait for moment and then you can attack. You'll know when. Two boomers will come down the stairs, try and take them out first. Then clean up the theron here. After that, head up the stairs they came from. Watch out for the Blood mounts up here. They will at you from the giant windows. There are quite a few torque bows around here. After you've dealt with the theron and the blood mounts, a Reaver will crash through the window. Use the torque bow on him. Once everything is cleared, head towards the window, restock on ammo and grenades and use the elevator.
The elevator will take a little while to get here. You don't actually need to kill everything, just survive for a certain amount of time (I believe). You'll probably run low on ammo though; remember that there is ammo by each elevator. That also means that it might be useless to destroy the pods, though it might slow down the rate at which the come at you. Keep destroying them as they come for you, don't worry so much about the distant enemies. Just jump on the elevator as soon as it arrives and you'll be off.
While on the lift, you will be attacked. It won't be anything too threatening. Just melee the hooks off when they try to grapple up and shoot anything at a distance. Eventually your lift will get hit and you need to mantel over to the other lift. Do so.
After you do that, the elevator will climb to the top and let you off. There will be some enemies, a Kantus amongst them. Kill them and then go around the balcony and down to the lower level. Across the room, you'll find a front desk and behind the column just to the right of that should be the last collectable. Grab it and start climbing back the way you came. Once you go up a level or two though, you'll get to the boss fight. The Locust Queen will try and blast you with Tempest (that thing she's flying). Just keep moving in between blasts. Before she blasts, put something between you and her and you'll be fine. When you get to the top floor, just be careful when you move and stay behind cover as much as possible. Just cut the three lines in between blasts she's done.
Once you're done, you will find yourself on an elevator. You will stop and get off at a maintenance hatch. To the right side you'll see a pile of boxes by the omen symbol. Destroy the boxes to get COG tags, and then continue left. Grab anything you can find, then smash through the door and clear this section of the room. Then look down the hall to the left. That's where you need to go. Work your way down. Kill what you can and use grenades to clear the troika if you have to.
When you get to the end, you'll have to choose to go left or right. Go right. You'll enter directly into a room with a few theron and a grinder. Take out the grinder and lob a grenade into the back of the room and hopeful you can thin them out pretty quickly. The security terminal is in the left part of the room. Return to the hall and go through the other door. It's really the same room without the mulcher. Clear this, flip the switch and then go into your dad's lab.
Good thing you made it down that hall. Now you need to make it back out. But first, grab the collectable by the window in the middle of the room. Then head out of the room. You could get on the troika or even just get behind some cover and just keep shooting. This section is pretty satisfying because there are a lot of lambent in a small space so they set each other off or you can kill many of them in row. Once you've cleared the hall and killed the stalk, get back to the elevator.
