How do I know how much water to add?

I've part of a bottle of cola extract.... I think I made 2 2-liter bottles from it a while back. How much water, and how much sugar do I use if I used say, one ounce and have 3 left? There are no mixing instructions on this little bottle.
Also, my plan is to boil the water to remove oxygen...should I boil prior to adding the syrup or post add? I'll be kegging this, BTW.

EDIT: Just noticed, this is a 2 ounce bottle, looks like 1.5- 1.75 ounces left in it.

No body has an idea on this?

Well, 3rd Google on it and I found it this time.... and now I have 3 gallons of Cola in a keg... I'll force carb it until tomorrow night and give it a try.

Man, I just love resurrecting threads. What's the verdict on the recipe?

Sounds like you just mixed cola extract (like the ones in the baking aisle?) with water and carbonated.