I think the way to remove kexts is as follows:

  1. In terminal navigate to /System/Library/Extensions/
  2. Issue: sudo kextunload nameofkext.kext
  3. Issue: sudo rm -rf /System/Library/Extensions/nameofkext.kext
You'll be asked for an admin password when you use sudo.

If you want you can reboot - it shouldn't be necessary.

Regards
Mike
VK3ZMH

Message: 1
Date: Mon, 17 Sep 2012 23:38:28 -0500
From: Guy Teague <accts@gtweb.org>
Subject: Re: [chirp_users] Please post
To: Discussion of CHIRP <chirp_users@intrepid.danplanet.com>
Message-ID:
<CACY9Dipm2WuNquOeqCrJAmfjFNCrUV_PFOdqNak55BeCLqNizA@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

hi folks:

[snip]
so i much appreciate all the help and tips and info you guys gave me and i
have no idea why i couldn't get anything to work until now. now i have some
more hours of research ahead of me to figure out how to uninstall the other
pl2303 drivers that are loaded and not working. it can't be good to have 3
drivers loaded into kext all for the same thing.

[snip]

/guy (73 de kg5vt)

On Thu, Sep 13, 2012 at 7:02 PM, Guy Teague <accts@gtweb.org> wrote: