I currently have an annual zones 2 - 4 Travelcard on an oyster (Due to
expire 31/12/08).

I am starting a new job where my boss will contribute £1500 towards travel.
My new job is in Zone 1.

I am thinking of buying a new Zone 1 - 4 annual, and then trading in my Zone
2 - 4 annual. Is this possible, and how much will I get back on my
remaining Zone 2 -4 ? Also, can this be done at any LU ticket office ?

Cheers