How to use AD/GPO/Print Services to "push out" a new printer driver to replace a broken one? How did my server get a broken driver?

Have you tried the latest driver update from the vendor's website? Relying on Microsoft for 3rd party drivers is a bad idea.

The trick to getting clients to download a new driver quickly is to edit the share path of the printer on the server. Change it (or even unshare it) for a minute or so, which will cause the printers to go offline. Then change it back to the original config. The clients will see that the printer is available again and will pull down a new driver if there is one available on the server.

They should do this anyway when they establish a new connection to the printer (after reboot, etc), but this makes it happen immediately.