This guide will cover the basics on how to export/backup your Minecraft server's MySQL database to your computer with HeidiSQL (Windows PC only).
First, make sure to download HeidiSQL and install it: http://www.heidisql.com/download.php
1. Start up HeidiSQL and click "New" on the bottom left corner of the window
2. On the left window, change "Unnamed" to whatever you want to name it. Then on the right window fill in the Hostname/IP, User, and Password with the ones shown to you in your Multicraft control panel's MySQL Database menu. Click save once done then click open to access your database.
3. With your database window now open, right-click your database name on the left side of the window and select "Export database as SQL" and the following window will come up:
4. Ensure your settings match the above and click the icon to the right of the "Filename" field to select where you wish to save the backup .sql file.
5. Click "Export" and wait until the process is completed.