Dandelion is very easy to eradicate. It is a broadleaf plant. Not
seeing your lawn makes it difficult to recommend a specific procedure.
If there are less than 200 plants, use a spot treatment by mixing up
Weed-B-Gone or Spectricide in a pressurized garden sprayer. I prefer
the "water-proof" products where it does not matter if it rains after
6 hours. Apply the treatment on a sunny dry day.