There is no auto update function in Pamela Call Recorder pre-4.5 version. In the latest 4.5 release we added an auto update function.

If you are on a pre 4.5 release you need to first uninstall the Pamela Call Recorder. Details here. All your recordings and (if present) license key information will remain.

Then click on the Tools menu in Skype 3.x and then "Do More" (In Skype 4 it is in menu "Extras" in "Conversations). Click on "Pamela MP3 Call Recorder". When you click on it, it installs automatically.

Note that any previous recordings will no longer show up in the list but they will be present in your "Pamela Call Recordings" folder in "My Documents" (usually present on your desktop directly).