Accessing a mysql database (old installation)

[leonardo De Araujo]

Hi All,
I am new to mySQL so this should be a very easy one.
We have an application that was installed on a server that collapsed.
We installed a new server but would like to get the data from the old DB into the new fresh one. I thought about doing a backup and restore but too late.
I have access to the filesystem of the dead system (all is ok).

How can I access a database that exists in an external hardrive, for example?
How do I connect so I can issue a mysqldump?

Thanks

Leonardo