If you have a wordpress installation and need to reset the password, because you are unable to login, and you have access to the database you can sort this out.
What you need to do is get into PhpAdmin or similar to query the tables, and update users table with the email address of the user that you wish to login as to yours.
Then go to the login page, and select the reset or I forgot password option, and put in the user name.
Check your email, quite often the spam folder, and you should see a link from which you can reset the password with. From that you should now be able to login!
There are always challenges when you buy an existing site and transfer it to your own server, and this can be one of them!
Good luck – let us know if you run into any other difficulties and we will do our best to help out.