Tape up a screwdriver so it wont scratch it, then you will be able to get under it to help get it out. Most likely your snap ring pliers are not big enough for the job. I have a good snap on set that the ends are taper cut so they wont slide off when you take the snap ring off.
Yes, that was the hot ticket. Tapered 45 degree bits pointing inward to each other . Was able to grab it and pull without the bits coming out of the holes.
I had to do 2 outer clips and 2 inner puck clips.
Done but it was not an easy job.
Now pumped 65 psi of air into the cannister and watching to see if any air escapes.
