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Since this is a hacked site, it makes a lot more sense to restore a backup on a clean site.

Start by downloading your backup archives locally. The backup archives are the .jpa, .zip, or .jps files in your backup output directory (default: administrator/components/com_akeebabackup/backup). There might be other files with a .j01, .j02, ... or .z01, .z02, ... extension; if they exist, they are part of your backup and you need to download them as well.

Keep a copy of these files, e.g. on a USB flash drive or a NAS. If things go wrong, this will be the only copy you have of your site.

Delete all of your site's files. This is important since your site was hacked. Restoring a backup only creates new files and overwrites existing files. It does NOT delete files. If your site is hacked, you probably have unwanted files from the hack lurking around.

Note: You do NOT need to delete your database. When restoring your site, in the database restoration step, there's a "With Existing" option in the right-hand sidebar. Select "Drop Same Prefix" and the restoration script will delete all database tables before restoring them from the backup.

Upload your backup archive file(s) and kickstart.php.

From that point, it's a straight restoration. If you are unsure how to do that, please refer to this video tutorial: https://www.akeeba.com/videos/1212-akeeba-backup/1618-abtc04-restore-site-new-server.html 

After finishing the restoration I recommend setting your site off-line, updating Joomla and all its extensions, make sure everything works fine, and only then put it back online.