sudo mount -o subvolid=5 /dev/<your disk here> /mnt
This will give you full access to the filesystem, then you can identify the full path of snapshots and delete them ie.
sudo btrfs subvolume delete /mnt/...
In openSUSE, snapper works by booting to a snapshot. “mount” command will reveal which subvolume you are booted from.
Make sure it doesn’t have anything valuable. Use rm -rf