daisey, they are fairly easy to lift; if you have several seedlings growing right on top of each other, lift them out as a clump, lay the clump on its side and ease them apart...

Do it on a cloudy morning once you are past hard freezes, maybe water the day before if it has been dry. The seedlings develop rather extensive root systems while still young, I pot them individually into 4x5" deep pots for some root depth.

Or, if you have room for a holding bed that has been amended with compost or is naturally high in organic matter, go ahead and transplant them there - prepared to water until they are older and established.