There are clips all the way around the phone. Use a flat blade knife and work your way around it slowly. I started at the top.
Two clips on top edge.
Two clips on the left and right hand side just below the top.
Two in the middle left and right.
two bottom left and right hand side.
No clips on bottom.
I bust the clips and also damaged the casing - hence my suggestion that you work carefully.
I then whiped the pad with a microfibre cloth. There were two sticky keys - green on button and the three button. Both had noticeably more mess over the PCB sections that were beneath the rubber buttons.
I cleaned up the keypad.
Put it all back together again.
It worked much much better than before.
I'm not expert, so just describing what I did, as a last ditch attempt to get mine to work.
Paulsk3
March 2007