How do I edit this plugin?

[Pickalo]

I have installed a plugin, but I need to change the way it works a little. Where can I access the plugin code and change it to better fit my needs?

[Princeton]

via the PLUGIN SYSTEM
(admincp -- located near the bottom)

[Pickalo]

Err, it is actually a product and I tried changing the code via the plugin editor and it had no effect.