What is the conversion for wire connections from a Lennox to a White-Rodgers 1F72-151.

The old connections were: G, W1, W2, Rc, Rh, Y1 and Y2.

The new connections are: W2, E, O/B ,R ,L ,G, C and Y

I have a Robertshaw 9420 Thermostat what does stage 1 mean and stage 2,need answer
Thank you Nora