As soon as you start this mission, you'll have to go to the marker on your map to get in a sniper's position, similar to the ones from Violence in Seattle. There will be a lot of Akurans in this battle, all coming from straight ahead on the streets. Make sure you use L3 to pinpoint the locations of the Akurans and take heed of the warnings that there is an enemy sniper, which should be easy to locate with their red sight.
Once you clear the Akurans at this location, Shane asks you to head to the next, which is on street level. This means that you won't have the luxury of the explosive Neon Bolts, and you will also need to watch your energy meter. There will also be a lot of Akurans here, with some snipers on the rooftops of nearby buildings.
There are a few spots around where you can drain Neon, should your health get low or you need some energy. Keep an eye on the number of Shane's men remaining and don't forget that you should get to use a Neon Singularity or two to help thin out the herd of Akurans. When you're finished at this location, the mission will be over.
