Take care of the dog right in the beginning, then look over to your left. Jump out to the bottle on the car hanging off the edge, but quickly jump back to the roof before the car falls. On the opposite side of the area there are two more bottles just sitting by themselves. In the back of the area is a card throwing enemy guarding two safes. When you've collected the bottles here, head over to the red neon arrow and climb up the neon tube to a higher section. Grab the bottle up there, then start making you way across the letters in Muggshot's name by jumping from neon tube to neon tube. Once you get to the "S", you can drop down to the next area.
Grab the two bottles below the "S", then carefully collect the bottles on the hanging cars. Under the tower here you'll find two hanging bottles above the enemy and then a standalone bottle in the corner of the area behind it. Head over to the dog in the middle of the area and take him out, then hang on the hook of the machine behind him to release eight bottles. Next break the safe on the side of the machine for two more bottles, then continue along the wall to three more bottles on the side of the area. When you've got everything, head back over to the "S" and continue along the letters until you can jump over to the middle level of the tower on the side. Grab the two bottles on the backside, then climb up to the very top where the tower will fall over and you will be in the next area.
Start off by taking out the two enemies up there, then use the red arrow on the side to get up to the top roof where a safe waits. Jump down one roof and on the front side, right above the checkpoint is another bottle. Jump back down to the lowest section of this area and head over to the other side where a card thrower waits. Take him out, then grab the bottle on the car and the two behind him. Head back over to the red arrow to get up to the first roof, then run along the walkways behind the sign and take out the hanging bottle on the first level. Keep climbing up to the very top, then run across and jump to a small tower that will fall over and let you into the next area.
Here you can take out the card thrower, then grab the bottle on the car, the one in the back of the area and the last one at the end of the crane. Go back over to the safe to input the code, then head back out to the end of the crane and jump down to the wrecking ball below. This will crash open the container below, giving you access to the key.