I do this all the time and I put the paste in a pan, add water or wine, stir it until I get the right thickness, keep adding the water/wine until it is right, add any spices I want, a tablespoon of...
Basically, you're going to need to reduce it by quite a bit to remove a lot of the water. I would put it in a saucepan and simmer (not boil) for quite a while, stirring every once and a while, and...
It is possible, but such a substitution is not always a great idea as tomato paste has a much more concentrated, stronger flavor and has less moisture. So the recipe with the replacement of tomato...