Use the M2EE tools to do the backup and restore process. Start the m2ee tools and type ? to see all the commands.
The one you are looking for is dumpdb to create a backup, emptydb to remove the database and files and restoredb to restore everything back.
I would suggest you try it on your accp environment first. Note that it will mean your application is offline for a couple of minutes depending on how large the database and how much files there are.
Regards,
Ronald
[EDIT]
See github for all the documentation https://github.com/mendix/m2ee-tools