Drop the gamedata folder into your main CoP directory and merge with the AO 2.2 gamedata folder. Starting a new game is requred. This is a beta patch...
Arsenal Overhaul is a full weapons conversion for S.T.A.L.K.E.R Call of Pripyat. All stock weapon models have been replaced with higher quality versions. Features 85 new weapons with 24 new ammunition types. All weapon sounds have been replaced with original sounds using real gun shots. Stalker NPC suits have been diversified and 6 new suits made available to purchase. The mod also comes standard with Atmosfear 3 and Absolute Nature 3 built in.
Arsenal Overhaul 2.3 is in development along side Arsenal Overhaul: Clear Sky 1.1. The next Clear Sky release will be first. After that all new weapons featured in the Clear Sky version will be imported into the Call of Pripyat version bringing the weapon count to 100 new weapons. Also included will be model replacements and all new scope textures currently featured in AO:CS.
New weapons so far:
TRG-22 - .308
TRG-42 - .338
Bizon-2-07 - 7.62x25
.357 Magnum JHP