Any holes you create in the soil won't stay. They'll just fill in when you water. That isn't a good solution, anyway, because even if the holes didn't fill in, the water would just flow out through the holes, and not stay in the soil long enough for the plants' roots to absorb it.
I really think you should repot the plants. If you handle them gently, the tomato plants should survive it just fine. They're pretty tough as plants go.
You can use the garden soil, if you like, but I prefer soilless mixes. They don't contain the pathogens found in soil mixes. A simple recipe to use the soil would be 1 part garden loam, 1 part finished compost, and 1 part perlite.
This site at the following link has a lot of information that will help you grow veggies of all kinds in containers. It also has a recommendation for a soil mix.
There are several more soil mix recipes at this link:
"Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?" - Douglas Adams