How to use liquid compost

If I've got some compost (mostly anaerobic) that is a few years old (composting in a garbage can), and just happens to be in liquid form for some odd reason, how much of that can I give to a very nitrogen-starved, transplanted tomato (not recently transplanted) that is a few inches tall? Do I just water it into the soil?

It smells like cow manure when I stir it. Is that normal? It's from fruit, produce scraps and such.