The safest way to modify config.xml is to do it from the Web-logic server administration console. While doing from this also the things that has to be kept in mind is that:

• Save a copy of the config.xml before making any modification to the original file. If there is any modification that causes error then it can prevent the web logic server also to start up. There is a possibility to revert back to the saved version of the file.

• Manually editing of the config.xml file, for a particular domain when, it is not active. If any changes are being made when the file is under use then those will be overwritten by the system. Any invalid XML or attribute value will be detected and the server won’t be able to boot. The information will be stored in this file.