I'm going to replace my old Trane Weathertron (Baystat 339A Heat Pump) mercury thermostat with a Filtrete 3M-30. I'm not sure of the wiring setup. On the old trane wearthetron I have

G O X2 Y T W B R

On my new 3M-30

C B O W2 W Y Y2 RH RC G A

I'm not sure how to connect these wires.

I appreciate any help / advice you may be able to provide Thanks