Remove the cover on the speaker side of the radio. You will need to loosen the 4 screws (2 on each side) that secure the SYNTH PCB Frame to the chassi. - You do not need to remove these screws - You need to remove the 4 screws that secure the SYNTH PCB to the metal frame.
Now flip the SYNTH PCB over, Locate the pins of the Microprocessor. In some versions of the HR2510 there may be Grey Epoxy covering one end of the Microprocessor. You may be able to peel the epoxy right off to expose the pins of the IC. If it is not soft enough to peel off, you can use a 400W hair dryer to heat the epoxy enough to remove it.
Cut the ground trace connected to pins 34 & 35, jump pins 34 & 35 to the free end of Resistor pack RR301 (see diagram) or connect a 4.5K -15K ohm resistor from pins 34 & 35 to pin 3 of IC312 (5V regulator).
This will give complete coverage from 26.000 MHz to 29.699 MHz (Some radios will go to 29.999 MHz)
Thanks toVE2XQQ for the mod and schematic.