BXVD3 Carb seized check valves

[Pricer]

I rebuilt this carb with a carb kit however two of the check valves would no free up.  One under the dash pot and other within the bowl but not under the accelerator pump.  i have left them in for the moment and was going to try it in the car.  If is determined to replace them, would it be wise to carefully drill out?  The brass sides have of the blade slot have almost been stripped off.  Thanks,