This is a multi-part quest to get the bridge open to the Neon. Your first objective is in the small park right below you. An engineer is guarded by two Dust Men. You have to take both out with a Precision head shock and you'll have to get the second within a few seconds after the first, or he'll kill the engineer.
The first Dust Man will be easy as they're just walking around. The second will be harder as he will start running as soon as you take out the first. Your best bet is to hit the one patrolling on the inside of the park first, then get a lead on the second one as he runs around the outside of the fence and let him have it as his head comes into range.
At the bridge[edit]
Next, you have to escort the engineer to the bridge controls. Lead him south along the east side of the canal and watch your mini-map for red dots spawning on the side streets. You'll be hit at least once, possibly twice on your way to the bridge. Use Shockwaves and Grenades to keep the Dust Men away and stunned while you pepper them with Lightning Bolts.
When you reach the bridge, you'll have to fend off two waves of Dust Men. Recharge quickly before the first wave comes into view. The first comes from the east and has a machine gunner. The Dust Men come in two columns, one to your left and one to your right as you look up the street. The machine gunner will be to your right. Run toward the Dust Men and throw a bunch of grenades down the right side of the street and then turn and deal with the left column. If you start to get hit by machine gun fire, throw some more grenades and then run back toward the engineer and take care of any Dust Men that got through your first attack. If the engineer is down, but not dead, heal him.
When the first wave is done, turn quickly to the west as the second wave is led by a bunch of kamikazes. If you have any energy left, throw some grenades. You can also start blowing up cars. Keep the kamikazes away from the engineer or you get to start over. Once the kamikazes are out (there are about four or five of them), you'll have a short breather to recharge before the rest of the Dust Men come in. There won't be many more and then the bridge is fixed. Or not.
Far side of the bridge[edit]
You'll have to jump/glide over the partially closed bridge and repeat this performance on the other side. Find the engineer in the park, Precision head shock the two Reapers (three on Hard mode) and then lead the engineer back to the bridge. If you've cleared out a large portion of the Neon, you may be able to get to the bridge uncontested.
Once at the bridge, defend the engineer against two waves of Reapers. After the Dust Men, this will seem like a picnic. The worst you will probably face is an RPG. After the second wave, the engineer on the other side of the bridge calls for help, so run over and fight off another group of Dust Men. This is a small group, and when they're done you have to run back to the other side of the bridge and kill more Reapers – a couple will be sniping from the rooftops.
Finally all the gang members are out and you just have to recharge the two bridge control panels. The bridge is down and the Neon is easily accessible. Now would be a good time to clear out the Neon and go on a hunt for Blast Shards. When you're ready, continue with Zeke's Request.