To Clean Volume, Tone and RF Gain Controls:

Remove Batterys
Remove Back Cover (7 screws)
Remove the main board (3 screws)
Release black plastive clips retaining the board near the battery compartment
Lift board from bottom edge and raise up 1-2 inches.

NOTE:
1) Make sure the sliders on the radio do not move while disambled.
2) Make sure the 2 ribbon cables on the component side of the board
   do not get disconnected.
3) Check closely for proper slider alignment of all swirches on reassembly.
4) Watch wiring on reassembly - especially the RED wire near the left bottom
   board reatiner clip and a BLUE and BLACK wire at the left (NEGATIVE) side of 
   the battery compartment.