Repairing spongey keys on a Casio CDP 200R SD 480p

I have a Casio CDP-200R which has some spongey black keys, and something rattling around inside, blocking other keys. In this video, I open it up and fix the keys, which were caused by the weighted arms on some keys coming loose.

[@TheRealArmor]

My reaction when my wife says you can't take apart this particular piano to clean it up.
"Bet"
To be fair i asked "can you take the keys off to clean under them?"