A MySQL MyISAM table is the combination of three files:
- The FRM file is the table definition.
- The MYD file is where the actual data is stored.
- The MYI file is where the indexes created on the table are stored.
You should be able to restore by copying them in your database folder (In linux, the default location is /var/lib/mysql/)
You should do it while the server is not running.
Hope it helps!!