Writing documentation is difficult and boring. The best way to go about it is to search the internet for a similar (but better) system and then to google translate the manual from English to English via Russian and Chinese. Then do quick skim and replace certain terms in order to make it seem that the documentation actually pertains to the in-house system. Pictures should be deleted, pixelated or replaced with random screenshots. The last step is to change the name of the author to the last person who was fired or quit.