Hey Bill,
This is the best time to separate them because the roots have not grown into each other yet. I would just carefully turn the pot over with your hand on the surface of the soil plants between your pointer finger and middle finger and remove the pot from the soil. Then gently break away the soil till the roots can be separated. The soil looks relatively dry and that's a good time to do this, you don't want to do this with wet soil. Then fill new pots with soil and use a pencil to make a hole deep enough for the roots and plant your seedling, water well. I have a tendency to over seed and end up transplanting many seedlings this way. Hope that helps good luck!

Eric