Welcome to the port of CS:GO's de_bank! A lot more interesting and fun than Trustee whether you stealth or blaze it. Anyway, head straight into the bank and make some noise.
Once the alarm gets tripped, the van will bail and leave behind the Thermal Drill. Grab that and set it up on the Vault door like usual.
Oh look, more deposit boxes. Crack some open until you find a money bag and grab it. Keep looting or hold out until the next part happens.
Wait a few minutes and the plane will fly over the map and drop three bags for a cage. Grab them...
...and take them to the designated area to build the cage! Now start moving the money bags up to it.
Once you've got all the bags into the cage, you can release the balloon! If you're in a rush, you only need to put one bag in the cage to let you release the balloon, and the cage doesn't even need cash in it to beat the mission.
The cage will release a balloon and the plane will be signalled. Hold out for his return.
Once the plane finally swings around, he'll try and catch the cage via the hook on the balloon. If he gets it, he'll fly away with whatever loot is in the cage leaving you with the rest. If he misses though, he'll need to take a few minutes to swing around and try again. Buy the Ace Pilot asset to improve chances of catching it.
One of the Manholes to the sewer will be highlighted for your escape. Open it up and jump down with any loot left over.
You now need to make your way through the maze of the sewer system to find your way out. If you have any loot left over, you need to carry that through too, all with a Point of no Return timer! There will be a dead end with a light and a ladder up to the van somewhere. Ditch the loot bags and bolt if you're running low on time.
Once you've sound the van, throw any leftover loot you managed to carry here into the back and escape.