Hello, I recently did this job for a reputable hydraulics shop. The pistons would not come off and from their 50 years of experience, knew if they forced it would likely damage the rod or piston. This is the option they came up with and had me do. Cut head off, repack, weld head back on. Rods are back on the excavator and working perfectly. Saved the customer a ton of money on new rod and/or piston.