1)you did a backup from your database but you don't know where is the file?
if yes then go to navicat, find backup and press right click on the file of your backup and then extract whereever you want
2)you have a backup file and you don't know how to add it on your database?
if yes then open navicat go backup press restore backup and find the direct location of your backup. if navicat can't recognise the file(maybe it is a .sql file) then make sure that l2jdb is clean and press right click on l2jdb(or whatever is the name of you database) and go to "Execute Bath File...". Find the location of the file and add it.
3)if it's something else then make clear what you want because none of us can understand!