To access the underside of the circuit board, remove the screws holding it to the chassis, remove the two screws on the underside of the chassis holding the back panel in place, and gently pull the back panel away from the chassis. Now you can lift the board. Use solder wick to remove excess solder from the holes where the caps are soldered and, while holding the iron to a connection, gently lift that side of the cap. Then do the same to the other side until the cap is free of the board. Do the same with the other cap. No other connections need to be unsoldered to do this.