2 way

My garage door is off the kitchen and the light switch in in the kitchen. Since I usually have boots and shoes in the garage in the winter I find I have to leave the door open so I can turn the lights off. I would like to have two 3 way switches, one in the kitchen and one in the garage so...

I have switch at bottom of stairs and switch at top - both operate light in middle. Light box in middle (light missing) has 2 black, 2 red and 2 white wires - I'm attaching new light with 1 black and 1 white wire (ignore earth for this question) what do I attach to what? asking as I tripped the...