Use a high wattage resistor with a value of 10-100 ohms per volt to be discharged and connect it from ground to the point to be dicharged. Check the voltage on all of the supply lines from the power supply. The easiest way to do this is to find the large caps or the diodes in the power supply secondary and measure the voltages. Any that have remaining voltage whould be discharged. After the set has been off for a while you likely will not have much residual voltage, but it is possible for the caps on the convergence supplies to hold a charge, which can discharge and damage a new IC or blow a fuse.