Decide on a unique name for this detector which will be denoted as DETECTOR_NAME in these instructions.
Create a directory called DETECTOR_NAME.
Copy the compact file to DETECTOR_NAME.
In the new compact file, change the name field to DETECTOR_NAME.
<info name="DETECTOR_TAG"/>
It is very important to change this tag. Otherwise, the detector conditions system will not recognize your new detector model.
Create a new file detector.properties in the DETECTOR_NAME directory which contains the following line.
DETECTOR_NAME: file:///path/to/DETECTOR_NAME
Make all the changes required to this compact description. Once you have a working compact description, it is advisable to permanently freeze this description and not make any more changes. If you want to change it later on, the best approach is to redo these instructions and create a new compact description and unique name.