3DSXL Circle Button Snapped. Where to get replacement?

Hey we have a 3DS XL Zelda edition. The circle pad joystick (on the left) the circle pad broke. Not the cover, but the pad itself.

I did some searching, but it’s not clear if I can get away with not dissecting the whole thing to replace just the plastic circle underneath the rubber part.

All the videos on iFixit they talk about replacing the underlying deal, but this is the pad itself that plugs into it. Any hints on how to get a replacement plastic part to slip the rubber cover back over?