PC200-8 Bucket Cylinder Piston Nut Size

I would like to have on hand the socket to remove piston so I can change rod seals. Can someone help me to find out what size is required? Is there any chance that my 1" impact gun will break it loose? My previous method on other large machines was to reinstall rod onto machine, block up piston with 6x6's, and use a 4ft Ridgid pipe wrench pushed down by another excavator. I don't have that luxury this time. Thank you in advance. Dan Romano D-ROM Machine Repair 3475028669

PC200-8 Bucket Cylinder Piston Nut Size