Update driver on deployed printer

Solution 1:

You want to change the driver pushed out by GPO. My guess would be that's why you can't update the drivers on most workstations, and "some" of the workstations aren't getting the new GPO applied - those ones are the one on which you can edit the settings/update the drivers. Correct it by correcting your GPO, rather than screwing around on each individual machine... which would seem to me to largely defeat the purpose of having GPOs.

(And yes, this is the "easy way" to redeploy this network printer. Change the installed printer settings in the GPO.)

Settings applied by GPO supersede local admin rights, which would be why you're getting access denied, even with administrator rights. (Which, by the way, is a really icky thing to give to all domain users. Nothing but trouble comes from it, trust me.)

Solution 2:

There's an old trick to make connected clients immediately update their print driver. Unshare the printer and then immediately reshare it under the same name. This will cause the printer to momentarily disconnect from the clients. Upon reconnecting, the clients will check the driver version as part of the process and download the latest drivers.