Go here: http://bir3yk.net/forum/topic_179/
Download the latest release of RevEmu.
Open the compressed file. The only folder you need is the "server" one. Take it and drop it on your desktop.
Take the "Steam.dll" file ηfrom the "server/bin" folder of RevEmu and put it in the folder of your server where the "srcds.exe" file is located.
Take the "rev.ini" file from the "server" folder of RevEmu and put it in the folder of your server where the "srcds.exe" file is located.
Rename your server's "steamclient.dll" file (in the "bin" folder of your server) to "steamclient_valve.dll".
Take the "steamclient.dll" file from the "server/bin" folder of RevEmu and put it in your server's "bin" folder.
Take the steam_appid.txt file and put it in the same folder as rev.ini file. The open it with notepad and change the number to 510.
Edit the "rev.ini" file that is in the same folder as the "srcds.exe" file. Find and edit the following lines like that:
SteamDll=.\bin\Steam.dll
ClientDLL=.\bin\steamclient_valve.dll (remove the "#" from this line)
Run your server and check it.