The question is ok, and here is my solution if u have root access to your server also phpmyadmin installed.
1. Login to your phpmyadmin
2. Export the needed databse and save it as a zip file or whatever option you have
3. login to your server and go to apaches webdir where your script is
4. make tar -cvf scriptfolder_backup_date.tar scriptfolder
5. Now you got a tar file which you can download or move to another server

To bring it back:
1. Delete old database in phpmyadmin
2. Import saved see more database
3. Login to server
4. Go to www dir
5. remove your scriptfolder
6. make sure your saved file is in www dir
7. type: tar -xvhf scriptfolder_backup_date.tar

Done.
Im doing that everytime when im installing a mod. So if anyhting is going wrong, i just bring back my old saved file. If everything went well, then i make a new backup of it.
Im dealing with version numbers in my backupfiles so i can see at whcih level i made a backup and what it contains.

Hope that helps a bit.

Jerry