How to extract the iOS 7 ipsw file from the dmg on a PC and apply it to your iDevice

First thing to do is to download the DMG file from Apple. Once you have downloaded it, here is how to push it to your iPhone

1. Extract the .IPSW file from the DMG. I used PeaZIP to open up the DMG file. Once you open it up, double-click on 2.hfs. the IPSW file is located inside of it.
2. Open up iTunes
3. Connect your iPhone/iPod/iPad to the PC
4. In iTunes, click on the device in the upper right corner
5. Make sure you perform a backup of your device. I a backup both to iCloud and my PC.
6. While holding down the shift key, click on Restore iPod/iPad/iPhone
7. Select the IPSW file to apply to the device

That is all that is to it.