Will only cover Part 2, chapters 1-4 of Dead Souls. I'll actually try to keep this spoiler free unlike the rest of the site.

Part 2, Chapter 1
Pretty much kill the Zombies and head for the pink markers. When you get out of the Tower, Majima will have to fight a boss. To defeat it shoot the rocky armour it has until you can see a red glowy on it's chest. Once that appears shoot the red thingy. Eventually it will get mad and decide to throw cars at you. Hit the heat-snipe button (aka Triangle) when the green exlamation symbol appears and then R1 and then whatever button you are told. Do that a couple times and it should fall. Then Majima has to head over to those Tojo idiots at Kamuro Hills (Park Ave, in the northeast section).

Part 2, Chapter 2
Once Majima is in Kamuro Hills, he'll have to go through the back enterance after he kills the Zombies. So once that is done head to the left and follow the path to the pink marker. Now you should be inside time to go up to the Super Market on the second floor. Head up the escalator and follow the path to the pink marker. There will be a scene and that's it.

Part 2, Chapter 3
You'll meet up with Dojima Daigo (the Sixth Chairman) and Azumi (head of the Asumi family). Majima will bark some orders and then when you wish to continue talked to Daigo and say you want to rest. Later some Tojo clan members crash open the barricade for the mall and let zombies in. When Majima and Daigo run out of the Super Market a crying child is heard and it's riled up the zombies. Clear out the zombies on the second floor and head towards the pink marker. Once the child is saved head down to the first floor and kill all the zombies there. Then run outside, Majima will protect the barricade while Daigo and the others repair the door. This part only last for a 2 or so minutes, and it's pretty easy, just kill zombies so they don't destroy the door. Once that is complete Daigo will rejoin Majima and they are surrounded until they see a light by the sewer and make a run for it. There is a boss fight with an Arahabaki Prototype similiar to the one at the end of Akiyama's chapters...but this on can turn invisible. No worries. Just keep shooting it and when it's invisible there will be a red glowy that you can see just shoot that and use heat snipes every chance you get. It should fall and then head for the sewer. Go all the way through the sewer to get to Purgatory and once you are there run to the pink marker at the end to talk to Kage. Scenes will play and then you are done with this part.

Part 2, Chapter 4
Go upstairs because Majima hates waiting, you'll meet up with Akiyama who wants to go to the batting cages. Anyway, when you are ready head there. Anything you want to complete as Majima do so now because you won't get another chance for a very long while. Let's assume you are ready, talk to Akiyama at the Batting Cages (it will be a pink marker area). Once inside there is a scene and a boss! (Also the person in white with Nikaido is man.) This boss, the Tsuchigumo Prototype, is a bit tough depending on what you have and Akiyama isn't the best partner in the world. Having Majima's ultimate weapon is very helpful and can be obtained by completing all his sub-stories. Just shoot it until it dies, stay out of range from it's attacks and when you get the chance to heat snipe take it. When it's hit points super very low meaning one shot left you will get the heat snipe option, take it because it's one of the best ones. Once the boss is defeated zombies will show up but that's the end of Majima's part and the start of Goda Ryuji's part.