If he is a "friend" of yours, you need to get new friends. You are not going to find any way around the distance restrictions, and legally you have NO STANDING to do anything. Many times these ordinances are designed so that there is virtually no place that a registered sex offender can live.
However, you need to find out first how the distance is calculated. Is it driving distance, based on the roads, or is it a straight line, like a bird flys. Get a good map and map out the parks and "day care" and see exactly what the distances are. Read the ordinance itself and have a good understanding of exactly what it means.
Then check the permits. It has been found that many day care "centers" are not properly licensed or permitted or that the physical location violates the rules and laws for a daycare center. Really the best way around your friend's problem is to have the daycare shut down if that is possible. It is kind of a long shot but it does work sometimes. There are lots of bad daycare operators out there.

