I did this on bass as it is generally easier than guitar. If you are competent player, you will only have trouble with the last few songs, you should should breeze through the rest. The real bogey song here is BYOB by System of a down. The way i beat it was to slow things right down in practice and practice until you are sure that you know the rythym and pace you should be alt-strumming at. Here is a video of the song