Factory reset navigation unit settings/data ?
 

Hi,

I just got a used Z Touring and I would like to restore factory settings of the navigation system, and also erase all previous data.

I've been in the hidden service menu, and there is an option to delete "User Data". I'm not sure if this is 100% safe, could you confirm I won't make a mistake by re-initializing user data ?

I don't want to delete some required car data by doing this.

thanks,