PHP Update problem

[opel]

When I updated my php BB using Fantastico I encountered a problem and the following intruction message appeared...

- Remove the directory /home/nuklearp/public_html/chat
- Untar /home/nuklearp/fantastico_backups/chat.backup.1126451394.tgz
- Empty the database nuklearp_phpbb2
- Import the file /home/nuklearp/fantastico_backups/chat/backup.sql into the database nuklearp_phpbb2
- Move /home/nuklearp/fantastico_backups/chat to /home/nuklearp/public_html/chat

I understand most of this except for:

1. how do I untar the file?

2. How do I import the backup sql file?


Cheers