Definitely leave the eggs on the rocks. Moving them from the rocks will most certainly damage them. As for the water level, leave it just like it was in the tank where the frogs laid the eggs. Also, make sure that the humidity is still high where you're keeping the eggs. If you're up for an experiment, try leaving the eggs in with the frogs. There is a chance that they will get eaten or damaged and won't hatch, but there is also a chance that they will survive. Again, if you move them, be very careful. Try to replicate the conditions as well as you can.
Alex