You can use Apache::Reload or Apache::StatINC, as already pointed out. However, I would suggest you just get over it and restart the server. It's so simple and fast, and it leaves no possibility for problems. I prefer it to the attempted magic approaches.

Incidentally, two expensive Java application servers that I have worked with require restarts to safely pick up changes in class files, and they take about 10 minutes to restart. You don't know how good you've got it until you sample the other side.