If you are really really gentle, you can wash your rootball off and place it into new soil. It is fairly stressing on your plants though so you may want to let them stay in veg another week or so after doing this.
If you are going to do it, take the plant out of its pot, put the rootball under slow running water, and let the water wash the soil away. Then gently set the plant into its new pot. Place the soil all around the root ball, being SUPER careful. Once this is done, water the plant well. Any air pockets should go away after this and you can fill the holes with soil. Then water again, and you should be fine.
As long as you are using a quality soil, it wont matter how much water you put through the pots at one time, you will not over water. Only if you water too often will you over water.