headphone cue buttons replaceable on DJM 400?

Hello,

Is it possible to replace the cue buttons on a DJM-400? I don't mean the plastic buttons that you see on the mixer but the actual buttons on the board. I don't see a part number for this piece.

The reason to replace them is because sometimes I need to really press down on the buttons for them to activate. Seems like the buttons themselves are wearing out. I already replaced the plastic cue buttons but that didn't help. If soldering is necessary that wouldn't be a problem, I'm just having an issue finding the parts.