Need help to replace print drivers

[tofast4U]

Hey guys, I have a print server with 700 printers on it.All Hp drivers. I need to find a better way to replace the driver.we have a corrupt driver and to reinstall it you need to disaassiate all the printer first then reinstall the driver and then point the printers back to the correct driver.As you see my problem here is I have over 140 print queues with this 2840 driver.There has to be a easier way to do this.Any idea's would be great.