I purcahsed a site from someone (a forum to be exact) and Im trying to import it into my forum.

This is all fine but I need the password that he has used for the database and I keep asking for it but not getting a response.

Is there some way that I can retreive it via phpMyAdmin or the MySQL database?

the databases don't have passwords set, it's the users in MySQL that have passwords set, then the users are granted permissions for databases, since you have access to phpMyAdmin you can reset the password for the MySQL user, in phpMyAdmin go to Privileges > find the user click edit on the right side > look at the third section it will have 'Change password' you can reset the password here