Yes it just slides off. Might need a tap left & right to free the gasket. But i don't want to send you there if its going to lead you into trouble. Not sure what to advise now, but unless you go there you'll never know & is going to keep rattling. Can you get a pic up the exhaust port with the piston skirt visible. I don't use ring compressors but you have ring pegs that stop the rings turning & getting caught in the ports. You have to be very careful with a compressor to get the rings exactly clamped over the pegs. There's generally a good taper lead in on the base of the cylinder & i just carefully poke the ring with a screwdriver while juggling the cylinder over. See what others say or i'll be teaching you all my bad habits.

I use my fingers to compress the rings when installing 

Me too. Just make sure pins are aligned with ring gaps.

Yes you're right of course. Fingers it is then!!. I didn't think that one out did i.. Been a while & i probably mostly use fingers, i know i do on the bench but a 360 80mm is quite big. I'll have to see what i do next time on mine.
I might get things started on an angle trapping one half of the ring then help it somehow or squeeze it to get other half compressed. Ring expanders behind the rings as some have doesn't help.
Think i'm getting yamaheimer's & can't remember. 52mm rings on an YL2 will squeeze easy by fingers. Worst ones are those that have next to no lead in on the cylinder.
Don't trap your fingers!!.