1. Go to Printers & Faxes
2. Delete the printer configuration in question. (For safety's sake, you may want to consider deleting all printer configurations to ensure that you aren't still using some element of the driver in another configuration somewhere. Remember that a driver is often times more than just a single file. It may involve shared libraries in use by multiple printer configurations.)
3. Go to File --> Server Properties
4. Go to the Drivers tab. You will be presented with a list of drivers.
5. Select a Driver and press the "Remove" button.