I pried one up one day on a passenger peg on my 750 ACE for no good reason.
I stretched it up on to the body using a screwdriver and thumbs, but didn't pull it over the end.
Mine were still pliable, but I can imagine if they have been baking in the sun for years things may be different.
They are quite thick and recessed deeply, there was no adhesive or if there once was it was long gone.
You might try using Windex as a lube, it works well and does not remain slimy like dish soap.
I don't think I've seen the replacement of the rings covered in any Service Manual, but there is a Honda General Service Manual that I don't have and they may be in there as the style was used on several models.
I already have the new o-rings and yes they're not that expensive. Fyi, no matter how slippery you make the peg, the o-rings refuse to slip over the flared ends of the footpeg. They fit into recessed channels on the pegs so the ID is quite narrow. Four hands might work. I, dunno. Thought it would be a 2 minute project.
As I said, I didn't try to pull one over the end.
I've got a seal puller around here somewhere that is little more than a thin, bent flat screwdriver with a 90 hook on the tip.
I'm wondering if you could work something like that through the inner diameter and use it as a tire lever and jack the ring over the rim at the end.
Maybe steam from a kettle might warm it up some without removing the peg.
2 minute projects never are are they?
It must be doable or they would not sell them separately.
Maybe there is an $80 Honda tool.
I thought of the tire spoon method as you stated by putting a bend at the screwdriver's tip. Why, every toolbox should have a bent screwdriver. Just never got around to it mainly because I'd need at least two bent screwdrivers. 50 zip ties would be easier than bending a second screwdriver.
Now people reading this might question the purpose of removing the o-rings with all the trouble it entails. Like what's the sense in all this replacing the footpeg o-rings since they last forever and any wear is cosmetic not structural.
In my case I had to replace a damaged footpeg and new footpegs aren't sold with the o-rings on them. Another example where removing the o-rings would be beneficial is swapping the o-rings on the passenger footpegs with the front footpegs to give the front footpegs new rubber.
Btw, there's nubs on the ID of the o-rings which prevent rotating the o-rings 180° to the unused side. The nubs fit into recesses designed to prevent the o-rings from rotating around the pegs causing the sole of your boot to slip, but the recesses are positioned in an asymmetric pattern.
Today I was looking at the o-rings and I think I've found the reason why they're almost impossible to pry off the foot pegs. The o-rings have two nubs (red x) that fit into recesses in the foot peg (red rectangle). I surmise the design is to prevent the o-rings from rotating and your boot from slipping.
The trouble with the nubs is that they decrease o-rings' ID and this reduced diameter is what makes it difficult to pry the o-rings over the flared ends of the foot pegs. When you're struggling to pry the o-rings over the flared ends like an idiot, you're looking at the OD of the o-rings and you don't notice the nubs hidden from your view. In this situation, ignorance ain't bliss. The o-rings are quite thick too.
Perhaps, a particular orientation would work. If you pry at A instead of randomly at Sector B etc. Otherwise, it remains just as futile as trying to pry the second side of a tire off the rim. The o-ring keeps slipping back.
Recap: the nubs protrude into the o-rings' ID. This has the effect of reducing the ID of the o-rings to diameter of a 25¢ coin (pic below). This makes it almost impossible to slip the o-rings over and off the flares at the ends of the pegs. Well without tearing the o-rings. The o-ring rubber is aged and even when new, the rubber is stiff. It's not pliable like the rubber on a rubber band even when new. The cross section is thick too.
I still have the o-rings on the old pegs seated in their channels, so for the heck of it, I'm gonna try flipping the o-rings inside out and see if that works (rectangle).