Navigate to the folder in XexMenu or Aurora and run the default.xex file. Games on Demand (GOD) Format (Best for Stock Dashboard)
For on a JTAG/RGH Xbox 360, you can either install it as an extracted game (XEX) for homebrew dashboards like Aurora or as Games on Demand (GOD) for the retail dashboard . Installation Methods Extracted XEX Format (Best for Aurora/FSD3)
Watchmen: The End Is Nigh - Ability/Item FAQ - Xbox 360 - GameFAQs
Use Iso2God to convert the ISO into a folder containing a series of numbers and letters.
Copy this folder to your internal hard drive ( HDD1:/Games/ ) or an external USB drive.
The game will automatically appear in your "My Games" section on the standard dashboard. Gameplay & Objectives
Use a tool like Xbox Image Browser or 360MPP to extract the ISO file into a folder.
Place the converted folder in HDD1:/Content/0000000000000000/ .