I believe you could figure it out, just might take a little trial and error to get it right and make sure everything is connected right. The directions in the book are pretty easy to follow but I purchased a second small book of Dr. Clark's called SyncrometerŽ Science
Laboratory Manual and it goes in more detail on how to build the zapper and a syncrometer.
The only thing I did was to buy a 555 chip with longer pins on it so it was easier to clip on the capacitor. I use mine all the time and love it so now I make them for others who don't have the time, knowledge or a Radio Shack near by but don't have hundreds of dollars to spend on zapper. If you have any more questions just let me know.