1995 Ford E-Series Van Air Pump Seized

Engine Mechanical problem
1995 Ford E-Series Van V8 Two Wheel Drive Automatic

Hi

I started up my 95 E-250 after several months and everything is OK apart from the Air Pump which is seized, meaning the belt is screeching over the pulley. Is there any way to free it up or is it a case of replacing the pump?

Thanks