as some of you are setting up steamgames with steam gui and there are some disadvantages in doing so (i.e. logging out on your desktop pc) here's how you can upgrade dedicated server using steamcmd pretty easy.
Download, unzip and execute steamcmd inside a folder i.e. D:\Steam (This will install the steam cmd client)
1. create a script lif_upgrade.cmd (go to explorer settings and untick hide file extensions on known files. Now click anywhere (Folder, Desktop etc.) and create a textfile. Rename it to something like lif_upgrade.cmd)
2. Copy&Paste and configure on your own wishes (be sure to configure steamcmdfolder to your installdir and also to configure lif installdir to fit your needs):
// You can enter valid values in here and commenting out the echo lines with double / if you are the only user of the server but I didn't recommend this!
echo enter Steam Username
set /P user=
echo enter Steam Password
set /P password=
D:\Steam\steamcmd.exe +login %user% %password% +force_install_dir D:\LiF +app_update 320850 +quit
3. Open the dir and read readme.txt