Xadrian can be modded by simply placing some XML and property files in a specific directory.
To begin go to the lib directory of the Xadrian installation and then create a new directory named data. From this new directory Xadrian reads the XML and property files. When a specific file is not found in the data directory then the corresponding built-in file is used so you don't have to overwrite all data files.
The following files can be stored in the data directory:
The games.xml file contains a list of available games Xadrian supports. For each game a subfolder with the game id as directory name can be created and this directory can contain the following files:
You can find the default XML and property files here. Simply download them, place them in the data directory and modify them as you like. I hope the simple structure of these files is self-explanatory.
The default property files (Containing the text messages of Xadrian) can be found here but you don't have to copy these files completely. Just create a new messages.properties file and only put modified or new messages into it.