How do I change back from MacPorts Python to system default version?

I used MacPorts to install a newer version of Python on my system (10.5.8 PPC), and then used the MacPorts select command to change the default invoked version of Python to the MP version. Now I want to change it back to the system version of Python, but I can't find a command to do so in the documentation. I know all the MacPorts command did was to change a bunch of links to point at the MP version instead of the system version. Unfortunately I don't know what all the affected files are. Does anyone know the command to reverse the setting or know the list of affected links that I would have to change?