Download 126.96.36.199 version and the 1.4.382 update(there's a shitton of tutorials on how to do that, Google a bit)->roughly 50 MBs
Download 188.8.131.52->roughly 1.2 GB
Download 184.108.40.206->only few MBs
Short summary of updating-download, extarct, copy/move to your game's folder.
Go to IW5M store, download and extarct DLCs, copy/move them to your game's folder.
Update your Tekno client/game to 220.127.116.11 and to 18.104.22.168.
Post back if you need any help.