Administrator has left the company and no one knows password - need assistance to reset

Your first option is to try admin to log in and admin as password, this may work.
If not - Google  Reckon Data Service they are able to remove passwords from your data file. The free version could take a week depending on the current workload. Express version is same day service if file is received by early on the day, if after 4pm you will receive it the following day at a cost of approximately $100.00