Compressor clutch removal

I am attempting to remove the compressor clutch on my 89 Astro equipped with a Harrison A/C compressor. I removed the shaft nut at the center of the clutch pulley and attempted to remove it with a puller and it wont budge. Does anyone know if there is a snap-ring hidden somewhere keeping it from comming off? If so, where?

Thanks

no snap ring you must have the proper puller to remove. they are very tight. auto parts have the proper puller.