look in the compartment up front where the controls are. There SHOULD be 2 phillips screws. Remove the knobs, remove those two screws. The box unhooks in back from the bezel! The power/volume knob is (2) 1/4 inch screws. The speaker unplugs from the chassis. as does the convergence and tuner. Watch the HV suction cup!
Unplug the yoke wires, and the chassis should ease out.
If it's like my 25LC20, the controls box can be hooked onto the front of the chassis and secured with a screw to hold it in there so it doesn't flop around.
Just look it over carefully, and it's pretty obvious once you do it the first time.