AC pulley does not spin

The bearing in the clutch pulley is probably seized. Being the clutch turns by hand, the cluch assembly, which will include a pulley, a clutch plate, and a coil, can be replaced, without replacing the entire compressor. This may require special tools, and compressor removal, and has to be done properly, or the compressor will be damaged. Sometimes a new clutch costs just as much as a remanufactured compressor assembly, which will already have a new clutch.