PC161 - how do you replace keys on this keyvboard?

[sunnysundberg]

I've got a PC161 keyboard controller and there is a loud sounding E key at the bottom of the keyboard. I'm guessing there is some debris collected where the key strikes the rubber controller. Has anyone taken off the keys on this keyboard? The key appear to be connected/seated differently from a K2500/2600. there is no notch the keys connect to on the key bed.

Sunny