restore plesk 12 on plesk 18

hello
i have a sever level full backup(size: 73GB) from my broken server that was used plesk 12.
that server is now, offline and unreachable.
now, i have a new server with plesk 18, how can i restore this backup?
also i have the old server's original backup folder that has 500GB size.

please note that it seams that according to that old server is offline , i can not use plesk migirator.