I have been given a "Bachmann's Big Hauler" with a few broken pieces and no instructions.  I'd like help knowing what I have and what I need to make this work.  Here is what I know:
Engine: Green with #7, and coal car that says "Atchison Topeka & Sante Fe"
Caboos: "Sante Fe, ATSF 425" with "Built 9-05"
Car: "Rio Grande", "D&RGWRR Royal Gorge ROute, Scenic Line"
Flat Car: "Ohio 1525"

I have about 8 pieces of tangent track, 12 pieces of curved track to form an oval (couple pieces broken), 

I have a remote control but I don't understand how this think gets power.  Is it battery powered - can't seem to get into any kind of battery compartment - is it AC or DC?  The tracks seem to be plastic so I'm guessing it is battery powered???
How do I get replacment track?