There 1 foot tall yes? What I would do at this point is just replant them into a bigger pot. If you try and pull them apart now you are risking killing one or both plants,or at best slowing there growth by shocking them.If you really want to get them apart the best way is to get a big container,fill it with room temp water,take the plants out of there pot and let them soak for about 15-20 mins.Then CAREFULLY and SLOWLY start to brake up the soil from the bottom up *let the water do most of the work*.Then once there apart you can transplant them into there own pots with fresh new soil *water after till all the soil is wet*.They still might be a bit shocked after this,but if your careful it can be done with minimal damage to your plants.