"There's no single ""right"" way to thin your vegetables if they've been planted to thickly. You certainly can transplant some of them to other parts of the garden. It's usually easiest to do this by digging the excess with a trowel, (trying to keep some soil around the roots), and moving them to the new location. Water the transplants in right away, and they may not even skip a beat.
If you just want to get rid of the excess plants, you can either hand weed them out of the row, which may cause the least disruption to the root system of those that remain, or you can hoe out the unwanted plants."