hi 

just installed the plugin and i go to change the .json file and it saves fine but when i restart the server it just gose back to the default settiings any idea how to fix

If a configuration file gets reset, that generally means it was not edited properly and was invalid JSON. I'd suggest making sure to follow the default format, and verifying if it is valid JSON by using a site such as http://www.jsonlint.com

Yup, what Wulf said .. :) but if you are able to validate it and it still resets, just shout back.