It depends on a few things.
If the disk has failed it may not be possible, this is why backups should be stored away from your HA drive, but you probably don’t want to here that right now 
If you have a windows machine you can get software to read linux disks
This will allow you to plug your SSD into a a usb port (with an adapter) and copy the backup.
If your system still boots up and you had samba addon installed you may sill be able to connect to the backup folder.
If you can still access the CLI you might find help here.
Good luck