I don't recall ever having to install one of these before. The PTFE Teflon ring is what I am concerned with. It is nearly like plastic! how in the world do I get that on without damage? They have to get installed somehow. Hopefully I am overthinking this!?
I’ve used hot water soaking to get tight seal rings to flex enough to install...may be an option for your situation
The old bobcats had a small aluminum piston in the hydraulic cylinders, a single square cross section teflon seal ring. Instructions were to boil in water for at least a minute, fish it out and immediately with gloved hands stretch it just enough to install into the groove. Fun. YMMV