For people not willing to download 1.3GB of data to remove a few files I updated the original ad removal post with TWRP install files
http://forum.xda-developers.com/showpost.php?p=67892852&postcount=567
It's only 3kb
This updated method remove the need of wiping the data and will remove all ads, even the one currently displayed on the lock screen.
Root or exposed are not required (only TWRP obviously) so it won't affect the device security.
I created 2 scripts, one to clean everything, the other one leave the Underground app store in the system, your choice.
If you use it a lot, it's nice as it will update the apps automatically without the need of allowing unknown sources.
OTA are disabled by renaming the updater. Safer than the previous method (pm disable and pm hide), and safer than deleting if we need it later.