Well, I'm running a Mac with Snow Leopard, and I've been trying to install the pickaclient. I downloaded the .jar file from one of the threads, but I don't really know what to do at this point. Where do I put the file exactly, and will I have to replace it with Minecraft?

P.S.- I've already tried to open the .jar file itself but that wouldn't work for some reason.

All help is appreciated.