You can't relocate the eggs unless they are on something you can remove from the tank. Most people try putting a tile where the clowns have laid in the past so that they cn move the tile with the eggs on it to a hatching tank the night they are expected to hatch. My clowns refuse to lay on a tile or smaller piece of liverock. So on hatch night I turn off all the lightd on the tank and in the room. Then I turn off the pumps and powerheads in the tank. After 30-60 minutes I check the tank and usually have fry everywhere. I shine a small light on the surface to attract the fry and then skim them off the surface and into a bowl to move them into the prepared fry tank.
Start stuffing your clowns with good food and you will soon see larger nests with healthier fry. Good broodstock nutrition will go a long way towards improving your chances of getting the larvae through meta.